As of roughly two days ago, I have not been receiving links or tabs sent to my desktop Firefox from my Android Firefox. I tried manually syncing, but it did not change the last sync time to "Now". My desktop FF also cannot see the open tabs on the Android FF. I disconnected the device and reconnected it, but it still does not sync. It's stuck on "Never" currently and I cannot even change what is synced or what the device is called. My Manage Devices showed two instances of the phone (the old name and the default). I disconnected both on my PC FF and the Phone FF did disconnect itself. It seems to be able to receive commands but not send them out.

Unrelated, but I have never been able to receive tabs sent to my Android Firefox ever since I started using FF on Android. That has persisted over three phones of different makes.