Rock 5A with Radxa Wireless Module A8 Bluetooth issue


I have a rock 5A running android. My Bluetooth works however not all devices will stay connected. I have it set up as a head unit in my car. I use a Bluetooth speaker amplifier which stays connected all the time. However my work iPhone 8 and my personal pixel 7a will connect and then disconnect straight away. I have tried unpairing/repairing, deleting devices, emptying caches etc but it hasn’t made a difference. Does anyone have any ideas for things I can try?