Not exactly sure when this started.. but for the past couple of months, my users on RDSservers (using FSLogix) are often having to re-authenticate to office apps as they are getting a yellow exclamation mark next to their names in top right corner. RDS servers all have unique machine ID's, shared activation is enabled... what else to look at?

Profile? Proxy?

shouldnt be any proxy.. what about profile?

I've seen more with UPM when AAD Appx package is not roamed correctly causing some authentication issues.

dsregcmd /status showing anything with user's prt?