majicalmaj Sadly your experience is all too common with (so-called) new OLM (it's been 'new' for 2+ years and is in my view lucky to be 40% as functional as OLD OLM, which until 16.73 was stable and solid.
If I was the MS 'lead' on (so-called) new OLM, I'd be looking for a new job, because it's a debacle of the first order... I do not know ANYONE who has been using old OLM that has positive things to say about (so-called) new OLM - apart from 'it looks nice'.
For those of you experiencing the IMAP 'mess' created by MS's OLM 16.73 updates (not fixed in 2 x updated versions of 16.74 either I hasten to add), I've found eM-Client pretty good (its stable and works with IMAP accounts). For now I've kept the "on My Computer" filestore of old OLM and did not migrate that to em-Client - I am using it to deal with the six (6) Yahoo accounts I have however.
The (so-called) "Support" levels 2 & 3 from MS is only accessible in US time zone - really helpful NOT for us here in Australia because it works out to be from 1800 - 0500 hrs... It's also only accessible via web chat - the (so-called) support function was removed from old OLM a couple of updates ago (very cute MS but not un-noticed if you're reading this!!)
Where to from here?
Based on the MS responses to date, it's not looking good for old OLM (to me), and (so-called) new OLM is a joke at best.
I am currently exploring options to transition back to OLW (yes Windows), and evaluating a migration tool from OLM format to PST format. I can run OLW in Parallels on my Mac (I have that already for other reasons) and the MS365 family licensing covers that. (I can't believe in 2023 I'm considering going back to Windows!!!). I did however notice that OLW has that 'dastardly' NEW Outlook switch - (my God the so-call NEW disease may have spread!!)
I will continue using my licensed version of eM-Client
I may try the support level 2/3 option which based on past experiences will 'burn' a lot of my time both in terms of logging the problem/detailed description, and responding... If that fails (and it has already for another poster here - they simply said 'too-hard'), I'll probably abandon OLM and unfortunately go back to the dark side of OLW... After 20+ years of OLM... But be assured, I won't go quietly!
Signed FRUSTRATED (originator of the thread on "When will MS release a fix to OLM for IMAP issues from 16.73...)
IanB