After more testing, this seems to either be my laptop's HDMI port, the TV's ports, or the cables ive used, as Windows also has this problem.
Makes sense, because I don't see any serious issues in the log.
- try another HDMI cable (if you buy a new one, get a 4K cable (a.k.a. HDMI 2.0 or 2.1))
- use the first HDMI port on your TV