Hello - I'm having the same exact thing happen i.e. Internet stops multiple times everyday. I see the modem system up time measured in hours not days!!! Currently it at 3h 53min.
I have an Orbi Mesh system connected to the Motorola MB8611 modem. I've had Xfinity/Comcast internet for years without trouble but this is driving me crazy.
Here are my Connection information. Please let me know if these numbers look off.