For around the last 6 months our internet service is repeatedly "crashing", requiring either a restart of the modem (T3200m) full function for a short period or time (as it inevitably continues to happen) or let the modem restart itself to reduced speed. The issue happened occasionally before the introduction of the Boost Extenders but now every single evening usually beginning at around 10.30 - 11pm.
I know something is crashing vs. service slowdown as wifi devices lose wifi service at the same time. Ethernet connected devices are equally affected.
Have you contacted technical support yet? If ethernet devices are affected as well, you will want to speak directly to technical support. It could be a hardware issue or something along the connection to your home.
If you find a post useful, please give the author a "Like" or mark as an accepted solution if it solves your trouble.