I did the even more dumbass version of this once.

I had DSL with a router and modem. I never had problems with it, never required reset etc. Over the years somehow I forgot and thought it was a combo router and modem.

Then when I finally had a problem, I insisted to customer support I had done many power cycles already. They scheduled a tech to come out, but I realized my mistake before it went that far at least.

A power cycle fixed the modem, of course.