Bluetooth problem either phone or my car?

[Android Central Question]

I've had my Huawei mate 20 Pro for a month now and I've had it connected to my car since day one and it's worked perfectly, but past couple of days when I make a phone call or receive a phone call while driving via Bluetooth the call sound is coming out the phone not the car speakers, I've tried everything and still the same yet it worked fine in the beginning.

Anyone had this problem before?