As you are a Moderator, I bet you acknowledge all of the problems related to creating/editing posts after updating to WordPress 5.0 in this forum.
I do, but there are really no more than the usual post-major-update-specific threads. I’ve been doing this for 14 years, I know what I’m looking at.
And of course, you also acknowledge how users fixed them.
Absolutely, we have a few listed here: https://www.ads-software.com/support/topic/read-this-first-wordpress-5-0-master-list/
Beyond those, we start with basic troubleshooting so that we can actually isolate the problem, reproduce it, and either fix it or direct to he offending plugin or theme’s support (or suggest an alternative). Without that, the best we could say is “works for me” (which it does).
Please turn back it to a normal plugin, an optional, not a default.
That ship has sailed, a lot of time and energy went into the new editor over the past 2 years, and we’re taking isolated issues like this as a chance to make it better, not roll it back.
For the best explanation of why the new editor exists, how it came to be, and what its future is, sit back and watch this: https://www.youtube.com/watch?v=aWlfp-1Q19I
Now with that out of the way, I’d appreciate it if you left the thread to rescuedog, myself, and anyone else willing to help them. That’s why we’re here.