I recently downloaded driver 19.12.2, for my Rx 5700 and my Memory clock says I am stuck at 1860 MHz in GPU Tweak, while GPU Tweak reads my ACTUAL max memory clock at 3500. I have uninstalled and reinstalled the drivers with DDU, to no effect.
I then ran a FireStrike to see if it read my clocks the same way, and it did. Below is a file to show the results.
EDIT: Re-installed Windows. Fixed.