I also received notification this morning about my PWS not sending data, along with, of course, notification about someone else's station in California. When I checked the link it appeared to be related not to my primary station, KLINC05, but my old and long-since discarded Acu-wrong station, KLINC47. Shortly after I updated the status of the inactive station indicating that it had been retired but not deleted due to WU policies, I received notification that my primary, and only, station was back on line.
Upon receiving the original 'inactive' notice I immediately checked my old, old Cisco DSL modem by which it connects along with its dedicated router either of which can at times crash. I was surprised that both were functioning normally and data was uploading to WU just fine, as a check of KLINC05 on WU confirmed.
My guess is that they're trying to at last clean up some of the dormant stations on their books, but also producing a few troublesome side-effects.