Each week after the weekly reset my Companion app cannot be used. My account appears to be signed in, but none of my data is available. I think it has to do with my account being linked between PS5 and Xbox. I have to sign out and back in every week to correct the issue.
-
Typically, each weekly reset is when the Bungie servers are undergoing maintenance and new patches are being released to clients. During that time, the API and Companion app are generally not available. This may explain your experience with the Companion app.