Home Internet router loses connection about every 5 days

Seems plausible. The router is in a window, however the issue has occurred at night as well as during the day,  and I’m using another router for WiFi access, so it would seem that the router shouldn’t be working that hard.

I can't seem to get pst the first level of tech support, which appears to be a person with little actual electronics knowledge that is just working off answerbook pages. Support claims that this is very unusual and that they have not had other reports of this, so I take what I am told with a grain of salt.