Heartbeat Timeout - Wyse 3040/5070 ThinOS 9.x RDP Win Server 2019

Does anyone know about the heartbeat issue? It disconnects the RDP session to Windows Server. I’ve set the heartbeat to the maximum (360 minutes if I recall correctly). I can't be sure if certain actions in Windows trigger this or if it's entirely between the thin client and WMS. I can't find any reason for this to be happening.

I can try to figure out how to update ThinOS since they're all running "Merlin" versions that I installed with USB drives and I think the latest Merlin is already 2 years old, while the latest ThinOS versions must be installed with WMS. I've downloaded and added the files, but sometimes I get errors about the file size... I'm hesitant to try to push these updates since I don't want a 5070 firmware going to a 3040 device and vice versa.