I have a problem, where the automatic fetching of the messages does not work anymore, even though it is checked in the options and set to every N minutes. Upon inspection I noticed that my two IMAP accounts show up in configuration as Protocol: "Local". However, clicking the root folder of the accounts launches IMAP fetch as usual. I checked accountrc and it says protocol=3. Is there anything else I can do for debugging?
Change the protocol number to 1 for imap accounts. The protocol numbers were changed a few version back, and the migration was automatic. However, you've used a new post-migration version, and then downgraded to a pre-migration version, the upgraded again.