Configured as before, it is running correctly, no data lost.
Glad you got it running again! Looks like something has damaged the container in a way during the update (just guessing here).
In any event, glad you are back on track.
Especially those SMTP things (what are they used for?)
For registration (if allowed), as well as a method of a password reset or lockdown
WEBSOCKET_ENABLED or TZ (Timezone)
Websock is used for the sync mechanisam that works in the background to sync any new item additions with all the clients in any direction (with some limitations that this non-official BW instance has). More details here
TZ is a timezone, just to keep the contianer in sync regarding time, that might be needed in case a password reset scenario happens.
DOMAIN I had since the start and from what I read back in the day was mandatory in order to run it over https to be compatible with the new version of official public BW clients. Looks like if it works for you without it, I could be wrong, but it runs for me just fine, so not sure what to tell you on that.
Btw. there are two lines missing now, if I compare to my previous (broken, now deleted) vaultwarden containe
With 1.26 version (looking at the change log) there were changes
that could have been a result of those changes. I wouldn't worry about that too much.