Iphone 15 connection with Sync

[S195]

Hello all
My son has just bought a 69 plate ST3. When he connects his iPhone 15 either by cable or Bluetooth he gets a lot of static noise which means he can't use the phone or play music. It's so bad he can't use apple play. It does not appear to be a speaker issue as the radio plays fine.
Any ideas - I appreciate this may be a known problem but I cannot find anything relating to it

 

[0nion]

Only thing I can think of is to try restarting the phone. Is there plenty of storage left on the phone and is the phone in "low power" mode or just regular?

 

[SteveS]

Test it with someone else's phone to see if it persists. If so, the problem may be with the screen/Sync unit. If it works fine, the problem is likely with his phone.