White screen when logging in
If you see a white screen with the text "Access denied" when trying to log in, your request has been blocked by Tesla. They do this for various reasons, in order to protect your account from abuse. All login traffic from VPN anonymizer services is blocked - this intermittently includes iCloud Private Relay. In order to fix this, disconnect any VPN services while logging in. After login, normal use should work fine while connected to VPN services.
Another cause for this error, is any man-in-the-middle inspection that changes the SSL certificate chain. Some corporate WiFi networks perform deep packet inspection or injects their own certificates in the SSL chain, in order to decrypt and inspect the traffic. When this happens, any login requests will be rejected by Tesla. In certain countries, even mobile carriers will do this. To circumvent this, during login, either disconnect from WiFi and use cellular data - or if the wireless carrier is the problem, connect to WiFi during login.