Possibly related to the new verified-users, unverified-users groups. If your forum had the require email confirmation setting on and you upgraded then registered-users no longer have posting privileges. This is done by the upgrade scripts. But if you reverted without doing a database restore then registered-users won't have the privileges back.
When reloading a website while writing a post, the title of the post doesn't get saved
OS: Ubuntu 16.04.5 LTS
Language: German (de-DE)
Installation directory: /srv/nodebb/
Guide used: https://docs.nodebb.org/installing/os/ubuntu/
When reloading the website (NodeBB) as a client while writing a post, the title of the post doesn't get saved, but the content does.
You should really be submitting bug reports to the NodeBB GitHub page, or the respective plugin page