davmail hangs *after* retrieving pop email from Exchange server

[Eric S Fraga <e.fraga@ucl.ac.uk>]

Hello,

TL;DR: how do I figure out what gnus is doing when it hangs after
downloading emails via davmail from an Exchange server?

Longer story: due to the introduction of multi-factor authentication
(MFA) in our institution, I have spent the past 2 days trying to find a
solution that allows me to continue using gnus.

For the record, one interesting albeit less than satisfying solution is
to run Thunderbird with pop access to the exchange server.  Thunderbird
supports OAuth2 access.  Then you can point gnus to the mbox format file
Thunderbird creates to store the downloaded emails.  This does mean
having to have Thunderbird running...

Davmail is the most often suggested solution.  It took some time to get
this working but it's sort of there.  I can download emails using pop
access.  However, for some reason, after retrieving the emails, gnus
hangs until I hit C-g and then the group buffer is updated.

So, my question is: how do I find out what is happening after the emails
have downloaded?  The davmail log doesn't show anything and neither does
*Messages*.  Are there gnus variables I can set to help me figure this
out?  It does seem that davmail has does everything it should and so has
gnus up to a point.

Thank you,
eric

-- 
Eric S Fraga via Emacs 28.0.50 & org 9.4.6 on Debian bullseye/sid