http://lpoaj76nfopd5lpinbskyqtroppamrzhhay3g4vvjm75st6ger34lbyd.onion/posts/2022/12/mystery-network-issue.html
Anyway, we had no idea whatta do anymore, so as a band-aid, we set up a timer that runs those ip link commands directly after each other once an hour. Ideally, that'll prevent this from happening in the first place (i.e. maybe't only happens'f the interface stays up for several hours at once), but even'f not, at the very least, it'll never last for more than an hour, even'f we're not at home, or take a whilea notice.