This is an older 5.1 SEPM, yes, I know it's not supported anymore. But I'm looking to fix it. Currently the only way is to manually switch the client.
I confirme this by deleting the entry in SEPM, made sure it's not in User or computer mode. And as soon as I re-install the agent, jumps to GroupB and in usermode. It's happening to all new or old builds.
Edit: Is there a debug log I can run on the backend to look at what's causing this behaviour?