My Iphone is connected to the car via wireless carplay. Technically, the onboarding works via bluetooth, then via the car's hotspot (SSID from the car). I have noticed that an SSID appears under the "known networks" that has no name. The SSID can no longer be deleted, not even with a network reset on the Iphone. I asked my car dealer if he could reproduce the problem with his Iphone and another car. And he can! So it's not my device, it's an Apple problem. To be precise: The fact that you can no longer delete the SSID is Apple's problem, why the car stores an SSID without a name on the Iphone when connecting is possibly the problem of the car manufacturer. Here are a few more screens on this case.
