Cannot publish remoteapp program

Single server 2019 remote desktop services cannot publish new remoteapp, although it does appear in program list. I can unpublish remoteapps
Event ID: 16393 Publishing failed . . .could not create a published application instance
Most solutions point to certs. A wildcard cert has been working for months, I changed to a new single cert, still same problem.
Same error in powershell. Restarted server a few times.
Any help? TIA