So just in case what I have tried to raise chances for fix:
Disabling HTTP2 - does not work
Increasing upload size in php - does not work
Disabling nginx reverse proxy and upload on LAN - does not work
Editing config.php ‘owerwriteprotocol’ = https - does not work
same as above for owerwritecli
Completely disabling Cloudflare proxy - does not work
Disabling gzip - does not work
Disabling few security headers - does not work
Tried desktop client for upload - does not work, same stucking
I dont have enough knowledge to tune up php.ini or www.conf for php-fpm maybe some hints on this that will work ?