For anyone encountering the same issue, use DXVK.
In my case the game called Black Squad was locked to the refresh rate, despite not having VRR (FreeSync), vsync or any fps limiter software, no fps limit set in-game, vsync forced off in Adrenaline, set Wait for Vertical Refresh to Always Off, Radeon Chill disabled, Enhanced Sync off, disabled fullscreen optimizations in windows compatibility settings, in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw there weren't a ForceRefreshRate setting. This game uses Unreal Engine 3, thus DirectX 9.
The only solution is to place the d3d9.dll from DXVK next to the game executable (not its launcher), and it should work, also, in the RTSS/Afterburner overlay the FPS should now show as VULKAN instead of D3D9.