apple mail disappearing

Hi all,

I would appreciate any guidance on how to deal with my Apple Mail issues. I have three accounts set up on Mail: icloud email set up as imap, comcast email set up as imap, and another comcast email set up as pop (no reason I know of as to why that one is pop). All the issues are on the comcast imap account, and here they are:

1) On the comcast imap account, when I delete an email, it doesn't go to trash. It's just gone. I can't undo the deletion and I can't find the email. On the other two account, it goes to the trash box associated with that account, and I can undo the deletion if I want.

2) I am getting hundreds of emails from a college alumnus group I belong to. I wanted to put them all in a separate folder to avoid clogging my inbox, and I could read them later. I clicked the little "plus" sign next to the Comcast account in the bar on the left side of Mail that lists my accounts in Mail. I created a new mailbox that is now listed along with inbox, drafts, sent, junk, trash for that Comcast account. However, when I drag an email from the inbox to that new box, it does disappear from the inbox, but it does not appear in the new college box.

If I use "ctrl-get info" for that comcast account, it says I have 249 messages in the trash, but I see none of them when I click on "show messages" or if I click on trash to see them. It says I have 25 in the newly created college mailbox, but it shows none when I click on "show messages" or click on the mailbox.

I called Apple and was told it was a problem with comcast and I should call them, but it sure seems like a software problem to me.

This is a 14 inch 2021 Macbook Pro M1 with 16GB RAM. I was running Monterey but updated to Ventura yesterday at the advice of the Apple support person. The update didn't change anything.

I would be very appreciative of any advice on how to pursue this problem. Thank you!