This kind of thing is very common, I have always had the same issues with the AMD cards on both my 2011 iMac (now just about retired) and my new 2019 one. Nvidia card users, regardless of bootcamp or PC, get to use Nvidia Inspector when this needs to be fixed. We can use RivaTuner Stats Server (RTSS) instead, alongside of the built-in Radeon Pro tools, to explicitly cap the fps to the refresh rate of our monitor which would be 60 Hz, so 60 fps. RTSS works in full screen or windowed mode, whereas vertical sync alone would only be effective in full screen.
https://www.guru3d.com/files-details/rtss-rivatuner-statistics-server-download.html
(note that the real downloads are 2/3 of the way down the page; ignore any in the upper right corner that might appear if you have no adblocker)
It's a pretty unusual program in that it has to be running alongside of the game to be effective, but it can be set to start up with Windows and uses next to no resources. Be sure to "minimize" it to the system tray rather than quitting it entirely after adjusting settings, it's easy to forget to do that.
