Using reference model 5700. Freesync is working normally in all other games and applications.
In CS:GO, with freesync off there is normal tearing as you would expect. When I enable freesync it is clearly enabled, because instead of tearing being randomly distributed, it is concentrated at the bottom of the screen. So there is no tearing in the top 3/4 of the screen, and constant tearing in the bottom 1/4.
The attached phone camera video has been slowed down to 50% to make it easier to see. In the second half of the video you can see the top portion screen has no tearing.
I'm using the in-game framerate limiter to limit FPS to well within the freesync range. It's definitely working as my monitor's OSD shows the refresh rate changing to match the FPS. It's just not fully working.