Linux Mint does not use very recent versions of the gfx drivers for that card (IIRC from last time I checked). My RX6600 therefore had some performance hit when I ran Mint (compared to Windows or other Linux distros). Arguably one could bump the installed versions of xserver-xorg-drivers-amdgpu and mesa-vulkan-drivers to more recent versions. You could have a look into the repo with Synaptic Package Manager and see whether there is a more recent version of the relevant stuff available (perhaps you need to allow for “testing” software source.