I can confirm the "problem with sync" issue, exactly as reported. I tried to pinpoint the error extensively, it is not auth-related, authorization happens, but then imap replies with "that's all she said" and dies. UI shows updating seemingly forever and then "problem with sync"

I also had a case of jolla-email doing 100% on both processors, I have a photo of htop, if you need that for forensics please ask.