I wonder how many of those could be fixed by simply rebooting the router.

I've had numerous problems with my own Time Warner Cable modem/router. It'd always become pretty bad after about 3 days of operation, dropping my speed to about 2% of what it was initially. I spend months debugging the damn thing, using a custom router, swapping cables, etc, and nothing would fix it.

Until I got a timer and got it to reboot every day at 3 am (the https://xkcd.com/1495 route) and never had the problem again.