One of my hats is to design/manufacture/sell GPS third party timing receivers for Cambium Radios. It seems like something happened around 2PM MST today which caused (at a minimum) certain Globaltop/Sierra Wireless GPS modules to quit receiving signals from the GPS constellations. Because these modules are pretty well respected as far as the quality of the timing signal (normally) and relative low cost, they tend to be integrated in a lot of devices, including my products, the official Cambium Products, and I understand the gear from other manufacturers.
So far, a power cycle/reset of the GPS module seems to solve the problem.
I haven't had enough time to process all of the data I have to know more details yet, but I can confirm the widespread nature of this event.