Right, seems there are some crossed wires here, if your framerate is not limited to 60, your problem is unrelated to vsync, whether adaptive or not. Ignore the UI for vsync, the fact it is showing Adaptive is meaningless, if you are getting >90 fps then vsync is off.
Stuttering/frame drops while moving around are due to graphics resource management (uploads of textures, models, shaders, etc). We have a variety of approaches to try and reduce the impact of this, but currently on Linux we take a basic approach. (Basic does not necessarily mean worse/slower, it depends on the driver.) Some changes to bring graphics resource management on par with other platforms are coming alongside threaded rendering support for Linux, but this is quite a while away. Linux will be among the last platforms to receive this, and there may be some unforeseen blocker that prevents it entirely so take this with a pinch of salt.
A lot of this is down to graphics drivers. It is possible that on your hardware the drivers are just better optimised on Windows.
All this said, if you are also getting stuttering and frame drops when rotating the camera without moving your player (ignoring the first few seconds in case shaders need compiled, and not in an area with lots of other players nearby), then the issue is something else