I've got an AGOL web map that feeds a Collector workflow. That webmap has 4 layers. They are all secured ArcGIS Server feature access services. Up until the other day, everything was working as intended but now, whenever I get into Collector and fire up the map in question, it no longer prompts me for my secure service credentials. It goes right into the map as if I've already given my credentials. If I go into AGOL on my PC and fire up the same web map, I'm immediately challenged with the secure service credential popup, as it should be. I'm totally baffled what's going on here. Any ideas?