I've found in my area that stores in one county started throwing "not authorized" on vanillas a couple months back, but the neighboring county has never failed for the full amount(literally like 2 miles apart but in technically different counties). I tend not to go back and test places often where payments failed, so maybe it was temporary. The onus is on you tho to test out different locations in your area. There's certainly no nationwide blackout tho. Yet...