Well for me it’s definitely that my Internet provider is flakey. I use it for work and have a kind of elaborate Internet back up system, so I monitor it more closely than most, and know what part of my network is down or unavailable.
So, if this happens 2x a month, and your network internally is hard wired I’m going to bet it’s outside of your house.
As always, if using Wifi, I recommend the use of a free Wifi analyzer you can get for any phone or laptop. Make sure you have both a solid signal and an uncontested channel. Hard to do in densely populated areas.

