Compatibility with QQ enterprise mail

My thunderbird’s version is 60.7.0. I use this mail client for more than 5 years. Our company used kinds of enterprise mail service in the past years, all of them worked perfectly with thunderbird except the QQ enterprise mail. I use this mail service in imap mode. When I read mails I find some mails disappeared and appear again a few minutes later. And the attached files are often damaged or the mails don’t have attached file when received by thunderbird since a few months ago.
The QQ enterprise mail works fine using foxmail which is a product of Tencent too.
Do any other person have similar problems or who can help me to fix it?
Thanks a lot!

I have never heard of qq so I can not offer you anything much. Other than to say this is not the support forum. It is here

Experience indicates that most issues with IMAP are a direct result of anti virus programs scanning the Thunderbird profile folder and attempting to scan encrypted connections. This is especially true where attachments are concerned.