I never updated a gpus firmeware and neither on the arch wiki or anywhere else did i find info about that. The only thing i know is that the propriatary Nvidia and the Nouveau drivers ship with firmware blobs for parts of the gpu. The tool “fwupdmgr” does detect my nvidia card but also has no updates for it.
But i think it is more likely software related. I cant imagine a hardware failure could make windows partially transparent (tho that could just be lacking imagination).
My monitor has a refresh rate of 165hz, but i have never seen an option called overdrive. But i think it is more likely to be a software issue. I dont think the monitor could cause a window to become partially transparent (at least i cant imagine).
Im running 2 1440p displays at 165hz. But i think display port version 1.4a should be able to handle that.
Oh, it seems I totally forgot to add that it is an Nvidia RTX 4080 (fixed that). And the drivers are the latest in the Arch repos. But it happened with previous versions too. The monitors are connected via Display cable, and switching / reseating those was one of the first things I tried. If it is a hardware failure, wouldn’t it happen all the time, or at least not under so specific circumstances? I play other games like Red Dead Redemption 2 that similarly tax my GPU, but never noticed anything like this.
Since you want an arch based dostro, i can highly recommend EndevourOS. Its comes with an easy to use installer, many desktop env options and a few quality of life tools like a comandline tool (nvidia-inst) to install nvidia drivers. And if you choose KDE Plasma in the installer, it will default to wayland.
AMD is still by far the better gpu choice for linux, but since explicit sync support is now in the 555 nvidia driver and kde plasma 6.1, most problems that nvidia had (i had) with wayland have seemingly just vanished. So no need to imeadiatly buy a new gpu.
Timeshift is great for getting your system back after a major fuckup. But i dont think it works as a backup solution that can be transplanted to other systems, but i never tried.
I use Kup to backup my important stuff. It comes with a kcm that integrates into KDEs settings menu and can do automated timed backups. Its a wrapper for bup. It also does Incremental backups.