Hi Ron,

I did some test using the up/down keyboard keys in Chrome, Firefox, Safari, and Edge and couldn't reproduce this. Are there any additional details you can provide? 

If you login to the same account from a different computer, do you get the same results? 

Is this happening on a specific account or multiple accounts?

I noticed when testing this that the initially selected message (the top, unread message in my Deleted Items in this case) will not be marked read when you arrow down to the next message in the list, but all other ones are updated. Is that what you're seeing Ron? 

If not, you might have a SignalR failure happening preventing those changes flushing back up to the server. If you open Developer Tools>Console in your browser, refresh, then reproduce the issue - do you see any console errors?