Hi,
Sorry but your solution can't be accepted. Please fully read my previous post. The problem is related with:
https://learn.microsoft.com/en-us/windows/application-management/per-user-services-in-windows
So please give me a solution for windows server 2019 where more services are generated by users which are connected there. This is not a problem with third party apps, but with some limitation on your system. Everything was fine on server 2016 or 2012 where some per user services were not created.
I'm awaiting for solution for you. Till today in my opinion windows server 2019 is not ready to apply RDS on this system. There are another issues related with splash screen which is described i another post etc...
So please wake up and give us correct update. As i see you didn't get feedback from me about it. Please believe me I'm working with your systems from many years and before i published this issue i checked everything which can be related with this issue.