I have been having the same issue with my Z Fold 3 and Tesla X since the last Android update on December 26th. I've tried many different ways suggested by other users and making up myself, but nothing did help. So, a few days ago I've opened a service request with Tesla not knowing if this problem is related with my Tesla car or with my phone (I only read about this issue in this forum a few minutes ago). Today, the Tesla tech guy stopped by my house (what a nice mobile service option!) After asking me what I have already tried with no success, he ran a few diagnostic tests on my car, found zero problems and then few minutes later called me out to show one of his emails showing that this is, indeed, a known issue currently being investigated by both Google and Tesla. No ETA when it'd be fixed.
So, far now, I've been using Watt Key watch app, which seems to working just fine as a key.