iPhone suddenly not recognised by CarPlay

I have a Honda Jazz Hybrid with CarPlay, and an iPhone 14 with iOS 17.3. CarPlay has worked perfectly for 3 years and three different iPhones. Yesterday, it suddenly stopped. So I restarted my phone, then asked Bluetooth and CarPlay to forget the car and started again. I can get a Bluetooth connection to the actual car for about 2 minutes, but CarPlay doesn't recognise that the phone is connected, and every time I tried to connect the phone the Bluetooth connection drops. Tried a friend's phone and same result, so it seems to be the car. Another thing that I don't fully understand is that in the past, when I've been using CarPlay, there are two wifi options, car-2cc5 and SGITTF. car-2cc5 seems to be essential for CarPlay to work, but it's disappeared from the wifi options.

I've booked the car in for an update to the infotainment system, but I wondered if anyone has had a similar experience, and can also explain what the wifi connections are! When I bought the car it was during Covid, the system was quite new, and nobody was available to explain it to me. I'd really like to know. Hope someone can help!