Precision 7550; i7 10850H CPU @ 2.70GHz; Win 10 Pro

1. Prior to plugging in a WD19TBS, task manager would show my CPU speed varying from 0.8 up to 4.3GHz (or so). Nice and fast.
   1. BIOS (1.7.0) shows turbo boost on
2. Plugged in the WD19TBS dock, and the cpu seems stuck at 0.81GHz, no matter what we plug into/out-of the dock, what programs are running, etc.
   1. Unplug dock and restart--no change.
   2. Unplug dock and cycle power: CPU back to 4.3GHz.
   3. Plug dock back in--CPU steadily downgrades to 0.8GHz in about 5-10 seconds
3. Dell support diddled with the system:
   1. Installed bios 1.8.0--no change
   2. Disabled some Windows services (non-MS)
   3. Went in to Dell Power Manager and chose "Ultra Performance"
   4. Set regedit key Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\intelppm from 3 to 4
      1. CPU now runs at 2.7GHz at all times
4. I then made the following changes:
   1. reset the intelppm/start key back to 3
   2. Unplugged dock
   3. Changed Dell Power Management to "Balanced"
   4. Cycle power: CPU now stuck at 0.81GHz.
   5. Changed Dell Power Management back to "Ultra"
   6. Cycle power: CPU now "stuck" at 2.7GHz. It's a noticeable slowdown.

How do I get my system back to where it was before all this started? I don't even care to get the dock working with it right now...I need my speed back.