ADT Hub sensor issues

I recently started having problems with my ADT sensors freezing status and no longer updating. It seems random. I have 9 door window sensors and 3 motion sensors. They all seemed to work fine for years. But a few months ago I noticed door chimes were gone. When I began to investigate, I noticed that several of my sensors were frozen in their status and would not update. I also noticed at the hub panel when I go to sensor check/walk around the sensors that are frozen are missing from the ADT hub. I keep deleting and readding the frozen ones back but they continue to freeze.