All cameras go offline simultaneously

Since about a year ago, all of my security cameras and doorbell (battery) go offline simultaneously, periodically...twice in the last month so now it's getting quite annoying. Why is this happening?! There are people with way more cameras and much bigger houses (greater wifi coverage required). We have 7 security cameras, and 1 doorbell camera, all working off the home's wifi (Uverse) with about 5 extenders (3 are Chimes) throughout the coverage area. Any ideas? When I call Ring support, they're really nice but basically tell me to power-reset my modem. This is ridiculous- did the Ring software change...what could be happening? The wifi hasn't changed and it's the most powerful/high-speed available, but our Ring products have started performing wonky.