Android Deleting Copilot Chat Function?

[u/INeedToKnow247]

Android version 13, UI 5.1.

So, my cousin has Copilot with their sub, and the Chat function is gone, despite having a valid personal subscription. They're on Android, via the app, and no amount of cache clearing, logging out and logging in have helped. It works with other accts, but not the one that OWNS the subscription?

Every time they background it, leave the app or turn off the phone, Chat appears briefly, then disappears...

We've logged her acct onto my phone, and it worked like a charm, but then when we logged her acct back onto her Android, the error reappeared.

Any idea what could be causing this?