IMAP and addon domains

I have just had someone report that IMAP is not working for their addon domains.
They have addon domains that were added yonks ago, and imap continues to work. BUT if a new email address is added to those doamins, the new email address auths fine with POP, but not for IMAP. Old accounts that were there previously continue to work.

using: WHM 10.6.0 cPanel 10.8.0-C41

is anyone else noticing this? Should I raise a bug for it, or is it a known issue? Or, am I doing something weird?

 

hrmm... Actually, IMAP is now failing for all domains/accounts.
Except main accounts

main accounts work fine, but email addresses fail.
kind of reminds me of when an up2date installed a newer imapd version over the cpanel one, but that should not be an issue with the full path to the cpanel version now in xinetd?

Any thoughts?
Thanks