Mail aging out of inbox

Hi. Running 5.804 on android 11. After a number of months stared messages dissappear from the inbox. They are not in the trash and they are still on the server. I don’t remember it doing this on earlier versions. I have not found any related settings. Suggestions? Thanks.

Messages don’t “age out”, but will fall off the K-9 message list if the count exceeds the “settings/fetching mail/local fo!der size” value that you have set.

They will still be in the mailbox and can be displayed by increasing that value or loading more messages.

Thanks, I’ll give it a try