iPhone messages not sounding

Afternoon, I hope someone out there can help me.

My iPhone 6s connects automatically to the Bluetooth every time I get into my 2018 Cooper S Convertible. Sat Nav and anything I play from the phone comes through the car speakers, however, when I get an email or text message, or indeed any notifications I dont get the usual tone either from the phone or through the speakers, phone calls do come over the speakers.

I never had this with either of my other two MINI’s Which both had Bluetooth, anyone got a similar issue or have any ideas as to how I can rectify it?

Thanks.