Steps to reproduce the issue

Mirgation from last joomla 3 to 4
System is stable, no errors, nothing, but simply save button disappear

Expected result

Can't save changes

Actual result

Can save changes

System information (as much as possible)

Only warring message is :

WarningThe PHP temporary folder is not set.
This folder is the folder that PHP uses to store an uploaded file before Joomla can access this file. Whilst the folder not being set isn't always a problem, if you are having issues with manifest files not being detected or uploaded files not being detected, setting this in your php.ini file might fix the issue.

its nonsense as far I see

Additional comments

Please Help !