Need to post your PC information like Make & Models and Windows and BIOS version installed.
That latest AMD driver is listed under the download page from AMD for your 6600XT GPU card.
Open Device Manager after installing the latest AMD driver and see if there are any errors indicated. If so upload a image of Device Manager showing the errors.
Also after installing the AMD driver run GPU-Z and upload the image to your reply. That will indicate if the AMD driver is working correctly or installed correctly.
Try installing a previous AMD driver and see if it fixes your problem: https://www.amd.com/en/support/downloads/previous-drivers.html/graphics/radeon-rx/radeon-rx-6000-ser...