WIFI "blocked" after ISP signal interruption

My apologies if there is another thread exists that discusses this issue. Also, apologies if I'm using the wrong terminology, I'm a bit out of my depths here.

Over the past couple of years I have had cable/signal issues with my ISP. They've had to send workers to replace the cable, sent me a new modem, and listen to me bumble through something I know very little about. The issue was resolved earlier this year and I have experienced uninterupted internet since then. Over the past couple of days my ISP has detected a regional issue that is causing an intermitent weak signal, which means that my modem is losing that signal frequetnly, but it's getting it back quickly. Exactly the same sort of issue I was having before.

What took me a while to figure this out was that my XR500 (for which I exclusively use WIFI) would say that there's no internet connection. On my android phone it would show up as an "!" over the WIFI symbol. By the time I noticed the internet stopped, I would go to where my router and modem are and the modem would show that it's connected to the internet (as it had time to get the signal back) but for some reason the XR500 wasn't "broadcasting" it. I have to turn the XR500 off and on in order to get the WIFI back

Can anyone help me understand why the XR500 blocks broadcasting WIFI after a signal interruption and reconnection from my ISP?