You don't sound ignorant at all. While you are doing the safe and correct thing to remote into the clients, what happens when you remote directly to the main computer?
Bit locker shouldn't have anything to do with it.
This is likely not it, but what happens if you go to the main computer, right-click on Computer, Properties, Advanced System Settings.
Then in the System Properties window, select the Advanced tab, select performance Settings, select the radio button Adjust for best performance. Then select the Advanced tab and under Processor scheduling, choose Background services. Click Apply, OK, then restart the computer. Just an idea.
