Question Problem with avatar upload and preview post

Hi to all,
I have lastest Joomla (3.9.21) and latest kunena (5.1.19) installed.

I haven't noticed exactly when (but I'm sure 2-3 months ago there wasn't any problem), but I see that the preview post is not working (it displays blank grey page).

Also I received message from users that they cannot upload avatar, they browse for the avatar, they press "upload" and the default grey head avatar is still there always.

I searched for solution here, I changed in the configuration - Avatars the option "Default avatar type" from icon to image but still the same.
Also I noticed that if I select an avatar from the gallery of kunena instead of upload a new one, then it works, but if I try to do it from the "upload" option in my profile then it doesn't work so the users can only select an avatar from my gallery of kunena (I have uploaded some avatars myself if any user prefer these)

This is my configuration report if you can find what causes these 2 problems (preview post and avatar upload).

Thank you.

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htaccess: Exists | PHP environment: Max execution time: 300 seconds | Max execution memory: 512M | Max file upload: 128M

Kunena menu details:

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ID	Name	Menutype	Link	Path	In trash
547	Forum	mainmenu	Itemid=538	forum1	No
538	Forum	kunenamenu	view=home&defaultmenu=540	forum	No
539	Ευρετήριο	kunenamenu	view=category&layout=list&catid=0	forum/index	No
540	Πρόσφατα Θέματα	kunenamenu	view=topics&mode=replies	forum/recent	No
541	Νέο Θέμα	kunenamenu	view=topic&layout=create&catid=	forum/newtopic	No
542	Χωρίς Απαντήσεις	kunenamenu	view=topics&mode=noreplies	forum/noreplies	No
543	Τα Θέματά μου	kunenamenu	view=topics&layout=user&mode=default&modetype=	forum/mylatest	No
544	Προφίλ	kunenamenu	view=user	forum/profile	No
545	Όροι Χρήσης	kunenamenu	view=misc	forum/terms-of-use-forum	No
546	Αναζήτηση	kunenamenu	view=search	forum/search	No

Joomla default template details : protostar | author: Kyle Ledbetter | version: 1.0 | creationdate: 4/30/2012

Kunena default template details : Crypsis | author: Kunena Team | version: 5.1.19 | creationdate: 2020-08-15

Kunena template params:

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DefaultCategoryicon	icon-folder
profileIconset	default
DefaultIconset	default
editorIconset	default
bootstrap	0
icomoon	1
tooltips	1
borderless	1
SubjectLengthMessage	85
fullactions	1
quick	0
displayMenu	1
displayDropdownMenu	1
displayDropdownContent	1
displayModule	1
displayBreadcrumb	1
displayAnnouncement	1
displayFooter	1
avatarPosition	left
avatarType	img-rounded
labels	0
whoisonlineName	both
formRecover	1
topicicontype	B2
fontawesome	0
socialshare	1
socialsharetag
socialtheme	classic
optional_username	0
writeaccess	0
localstorage	0
IconColor	inherit
IconColorNew	#48a348
editor	0
video	1
maps	1
emoticons	1
twitter	1
ebay	1
link	1
picture	1
hide	1
spoiler	1
table	1
code	1
quote	1
divider	1
instagram	1
soundcloud	1
confidential	1
hr	1
listitem	1
supscript	1
subscript	1
numericlist	1
bulletedlist	1
alignright	1
alignleft	1
center	1
underline	1
italic	1
bold	1
strikethrough	1
colors	1
size	1
wysibb	bold,italic,underline,strike,sup,sub,justifyleft,justifycenter,justifyright,|,img,video,link,|,bullist,numlist,|,fontcolor,fontsize,fontfamily,|,quote,code,table,removeFormat
avatarSizeX	40
avatarSizeY	90
avatarSizeXThumb	36
avatarSizeYThumb	36
avatarSizeXWelcome	72
avatarSizeYWelcome	72
avatarSizeXList	36
avatarSizeYList	36
avatarSizeXPost	144
avatarSizeYPost	144
avatarSizeXProfile	200
avatarSizeYProfile	200
templatebyText
templatebyName
templatebyLink

Kunena version detailed: Kunena 5.1.19 | 2020-08-15 [ Tethys ]
| Kunena detailed configuration:

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Kunena config settings:
board_offline	0
enablerss	1
threads_per_page	25
messages_per_page	15
messages_per_page_search	15
showhistory	1
historylimit	6
shownew	1
disemoticons	0
template	crypsis
showannouncement	1
avataroncat	1
catimagepath	category_images/
showchildcaticon	1
rtewidth	450
rteheight	300
enableforumjump	1
reportmsg	0
username	1
askemail	0
showemail	0
showuserstats	1
showkarma	0
useredit	1
useredittime	349200
useredittimegrace	3800
editmarkup	0
allowsubscriptions	0
subscriptionschecked	0
allowfavorites	1
maxsubject	85
maxsig	2600
regonly	0
pubwrite	0
floodprotection	0
mailmod	0
mailadmin	0
captcha	0
mailfull	0
allowavatarupload	1
allowavatargallery	1
avatarquality	96
avatarsize	1600
imageheight	1200
imagewidth	1600
imagesize	3000
filetypes	txt,rtf,doc,pdf,zip,tar.gz,tgz,tar.bz2,rar,jpg,jpeg,gif,png,bmp,docx,xls,xlsx
filesize	21000
showranking	1
rankimages	1
userlist_rows	30
userlist_online	1
userlist_avatar	1
userlist_posts	1
userlist_karma	0
userlist_email	0
userlist_joindate	1
userlist_lastvisitdate	1
userlist_userhits	1
latestcategory	0
showstats	1
showwhoisonline	1
showgenstats	1
showpopuserstats	1
popusercount	5
showpopsubjectstats	1
popsubjectcount	5
showspoilertag	1
showvideotag	1
showebaytag	1
trimlongurls	1
trimlongurlsfront	40
trimlongurlsback	20
autoembedyoutube	1
autoembedebay	1
ebaylanguagecode	en-us
sessiontimeout	3600
highlightcode	0
rss_type	topic
rss_timelimit	month
rss_limit	100
rss_included_categories
rss_excluded_categories
rss_specification	rss2.0
rss_allow_html	1
rss_author_format	name
rss_author_in_title	1
rss_word_count	0
rss_old_titles	1
rss_cache	900
defaultpage	recent
default_sort	asc
sef	1
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pollenabled	1
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polltimebtvotes	00:15:00
pollnbvotesbyuser	100
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allow_user_edit_poll	0
maxpersotext	350
ordering_system	mesid
post_dateformat	datetime
post_dateformat_hover	datetime
hide_ip	1
imagetypes	jpg,jpeg,gif,png,bmp
checkmimetypes	1
imagemimetypes	image/jpeg,image/jpg,image/gif,image/png
imagequality	99
thumbheight	32
thumbwidth	32
hideuserprofileinfo	put_empty
boxghostmessage	0
userdeletetmessage	0
latestcategory_in	1
topicicons	1
debug	0
catsautosubscribed	0
showbannedreason	1
showthankyou	1
showpopthankyoustats	1
popthankscount	5
mod_see_deleted	0
bbcode_img_secure	image
listcat_show_moderators	0
lightbox	1
show_list_time	8760
show_session_type	0
show_session_starttime	0
userlist_allowed	0
userlist_count_users	1
enable_threaded_layouts	0
category_subscriptions	post
topic_subscriptions	every
pubprofile	0
thankyou_max	50
email_recipient_count	0
email_recipient_privacy	bcc
captcha_post_limit	0
image_upload	registered
file_upload	registered
topic_layout	flat
time_to_create_page	1
show_imgfiles_manage_profile	1
hold_newusers_posts	0
hold_guest_posts	0
attachment_limit	50
pickup_category	0
article_display	intro
send_emails	1
fallback_english	1
cache	1
cache_time	120
iptracking	1
rss_feedburner_url
autolink	1
access_component	0
statslink_allowed	1
superadmin_userlist	0
legacy_urls	1
attachment_protection	0
categoryicons	1
avatarresizemethod	1
avatarcrop	0
user_report	1
searchtime	all
teaser	0
ebay_language	0
allow_change_subject	0
max_links	100
read_only	0
ratingenabled	0
url_subject_topic	0
log_moderation	1
attach_start	0
attach_end	14
attachment_utf8	1
autoembedsoundcloud	1
emailheader	/media/kunena/email/hero-wide.png
user_status	0
signature	1
personal	1
social	1
plain_email	0
moderator_permdelete	0
avatartypes	gif, jpeg, jpg, png
smartlinking	0
defaultavatar	nophoto.png
defaultavatarsmall	s_nophoto.png
quickreply	1
avataredit	0
activemenuitem
mainmenu_id
home_id
index_id
moderators_id
topiclist_id
misc_id
profile_id
search_id
avatar_type	1
sef_redirect	1
allow_edit_poll	1
use_system_emails	0
autoembedinstagram	1
disable_re	0
email_sender_name
display_filename_attachment	0
recaptcha_publickey	6LeuedUSAAAAANGd-R7GtbNYkR3DsNsPhcKYynUV
recaptcha_privatekey	6LeuedUSAAAAAPwbpvClR7uVTRSts7g4PVhFdlFk
recaptcha_theme	white
keywords	0
userkeywords	0
userlist_name	1
usernamechange	0
version_check	1
userlist_usertype	0
sefutf8	0
enablepdf	1
jmambot	0
annmodid	62
changename	0
userlist_username	1
rules_infb	1
help_infb	1
onlineusers	1

| Kunena integration settings:

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Kunena - Finder Disabled
Kunena - AltaUserPoints Disabled
Kunena - Community Builder Disabled
Kunena - Easyblog Disabled
Kunena - Easyprofile Disabled
Kunena - Easysocial Disabled
Kunena - Gravatar Disabled
Kunena - JomSocial Disabled
Kunena - Joomla Enabled: access=1 login=1
Kunena - Kunena Enabled: avatar=1 profile=1
Kunena - UddeIM Enabled: private=1

| Joomla! detailed language files installed:

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Joomla! languages installed:
en-GB	English (United Kingdom)
el-GR	Greek (el-GR)

Third-party components: UddeIM 4.0

Third-party SEF components: None

Plugins: Search - Kunena Search 5.1.2

Modules: Kunena Latest 5.1.2

Yes, that's two known bugs. The avatar upload you can solve the problem for now, if you allow direct component access (Configuration -> tab General -> Direct Component Access = Yes).
For the second bug "preview" I have unfortunately no solution at the moment.