I have had endless problems for the last several weeks with phone as a key. My 2023 MYLR wouldn't unlock as I approached, stopped locking when I walked away, and in order for me to be able to drive with the phone as a key, I would have to go into the Tesla app and hit the "Start" button under Controls, as this would enable Keyless Driving. This morning in an attempt to solve the issue, I uninstalled the Tesla app from my phone (Samsung Galaxy Fold 3), went into the bluetooth settings, unpaired the phone from the Tesla MYLR, disabled Bluetooth, reenabled Bluetooth and redownload the Tesla app, then went to the MYLR, deleted my phone as a key, and removed the phone from the paired device list (it was the only one).
From there I repaired my phone and the MYLR via Bluetooth. Then I tried to add my phone as a key. The process is a failure every time. In the Tesla app, the phone receives an error message saying it can't connect and then says "Rety". I was able to finally get a different response, if I place the phone directly on the area where you normally place the key card. Then it connects, however, it still gets the same error message in the app, even though the car says the key has been set up. Once I took the phone off the NFC area and put it on the charger, it's font on the key screen turned from black to grey and when I pushed the brake to try to shift into Reverse, I got the message that I needed to use a keycard to drive.
Up until a couple weeks ago, my phone as a key worked decently well. I say decently well because it would always unlock the driver door and let me drive, and locked the doors when I walk away, save for an update in January that was resolved. The part that has never worked for me is that the non-driver doors and the hatchback will not open unless I manually go into the app and unlock the care even if I am physically touching the car with my phone.