I have an SQ1 model of the Surface Pro X (which is an arm-based processor) and running the native arm64 version of Firefox was the best choice to get the most performance out of the tablet. However...
I'm experiencing weird glitches throughout the entire browser (most likely areas where 2D rendering is involved). Most rounded corner assets appears as square corners and their colors seems to either be incorrectly rendered or have weird square seizures. The image below shows the issue.
This issue has happened ever since I got the device which was around the time 118.0 was out. It happens on both the original Windows 11 and the 22H2/23H2 update and no amount of driver updates made the problem go away (the driver is the latest one listed on Microsoft's site, 27.20.2020.0). Disabling hardware acceleration does solve the problem but that leaves the performance being trash.
I'm not entirely sure if this is a Qualcomm/Windows problem or a Firefox problem. I've had a phone running Windows 11 on arm with the same native arm64 Firefox and the issue did not occur, so I guess it's just this tablet model.
I do have a Reddit post with a video demonstrating the issue here. If any of you reading this are developers please look into this issue as I don't want to switch to the x64 version because emulation performance on this is horrible.