I have my iPhone paired to my 2009 rx but having trouble using it. Specific problem is that it won’t pick up an incoming calls quickly. The incoming call goes to voice mail before the rx recognizes it.

 

I think you're better off buying a bluetooth dongle at this point as the bluetooth on the phone is very old. Albeit my wife was using the built in bluetooth as recently as 2020 with no issues with whatever iphone was modern at the time.

the following is one that simply "just works"

 

Good idea! thank you