Email disappears after moving to a folder

One of the emails in my inbox disappeared when I moved it to a different folder. The move seemed to have executed normally, but as I watched it simply vanished from the folder to which it was moved. I look in trash, all the other folders and checked the server through a web browser: no email! I am using Apple mail as a client for ATT/Yahoo email. I do have rules set on both the server and in Apple mail, but none of them would have filter the specific email.

Using OSX Ventura 13.5 on an iMac with plenty of disk space, memory, and cpu.

What is going on?

Thanks,

John