I'm having a problem I'm not quite sure how to tackle: every other startup or so results in a black screen. Usually nothing gets printed (no bios splash, not GRUB menu, no OpenRC prints), and the monitor goes to low power mode after a while (I haven't quite confirmed if this is actually the case, or if everything happens before my monitor have actually stated, but I'd expect the GRUB menu would hang long enough for it to do so).

However, it does wake up if I switch to another TTY (e.g. ctrl+alt+F4) and lets me log on, so it has obviously booted up. If I switch back to TTY 8 from there it just shows a blinking cursor (i.e. not SDDM, which is what I'd expect). If I reboot from the TTY that lets me log on, the boot process is usually normal and leaves me at the SDDM login.