iCloud mail disappearing

I first reported this to Apple 2-3 years ago and still when I get new mail, from any random sender, it will disappear before I can read it.

This goes for any of my iDevices, my Mac, and even iCloud on the web.

The advisor managed to rebuild my mailbox and was able to retrieve the disappeared mail.

I'm still experiencing the same issue - they don't get deleted or moved to any other folder - they just simply vanish!

Is this an ongoing iCloud server issue?

I can't believe this is still happening.