OK, I just had a look through your logs and what a tangled web you have woven.
The problem with logs is they can find you out. Where was this mentioned? Not anywhere in your lists.
beastserver yum[5367]: Erased: smeserver-affa
I'd like you to open these two logs and then tell us what you have really been up to, because it isn't anything like you have outlined here so far.
cat messages.20210711114349
cat messages.20210711114350
I'm pretty sure you have seen a mountain of errors already but are hoping that you can just resolve them on v10.
Your problems started long before you ever got to v10. You are not going to resolve them on v10 either.
My little guess.
You borked your v9, probably with owncloud but I think you might have had wordpress on there somewhere at some point? maybe that was the issue and you got hacked - so decided to restore it from an affa server. But unfortunately that backup was also borked.
So you decided that you would run a standard backup and then install that on v10 and then fix it from there.
That's my rough guess - might not be quite right, but not far away.
Sorry to sound a bit cynical but you could have saved us 5 pages of running around and comments if you had told us the whole situation from the start.
My suggestion is you create a new v10, re-create all your users and groups, take your basic data and email directories and copy them to the new server, and update the file usernames and groups accordingly.