Mail rules not saving set Mailbox 14.7.6 for Gmail account/s

Every day when I start up my Mac the first thing I have to do is go into my Mail Rules & reattach the mailbox to the rules again.

For some reason now it's no longer remembering that I chose a mailbox to move the message to.

I have 30 Rules in use & have used the same ones since mail was first launched.

most of my rules are basic, xxxxx@xxx move to mailbox xxxxx

& then the Spam & just are removed & I can keep a 0 Inbox.

I have 6 Email addresses connected. & it's only the rules connected to my main email that seem to be forgotten. so when I start up Mail I have MANY pop ups telling me that the mail could not be redirected because the mail box does not exist. They do they are there The rules just forgot to save it for next time.

I have rebuilt the mail boxes, checked the IMAP settings, logged out & logged back in.

I have removed the account & re-added the account/s.

I can send & receive mail from the Gmail account.

My other Gmail accounts are fine & their rules seem to work. oddly..

It's VERY annoying to have to do this all the time!

I have seen "fixes" that recommend going into safe mode but obviously this is not my issue as it's about Mail saving the destination.

I feel that because I have had this Gmail account since the first week of Gmails announcement (it was invite only back then) that its old & has Alzheimers.. The poor thing.

The only issue is its not a Gmail issue it's a mail Issue.

Any input would be amazing!

Cheers

Sunda