I've had this problem for a few months now. I've called Samsung tech support several times. So far they have not been able to solve this issue.
The sound on the phone cuts in and out. I'm talking about sound from the external speakers and also the internal speaker that you listen to when talking on the phone.
The problem happens when the watch is connected via Bluetooth to the phone and the Bluetooth switch for Calls is set to ON, on the phone. You can find that setting by going to your Bluetooth list of paired devices, then clicking on details at the bottom of the screen, then clicking on the settings icon (a gear) next to the Galaxy Watch 5 Pro. You'll see a switch that's labeled Calls. It needs to be ON to use the phone to take phone calls and talk on the Watch whether you have LTE or not.
The only thing that will stop this from happening is to turn the Calls setting off in the Bluetooth setting for the watch on the phone.
I've tried resetting the watch and reconnecting it to the phone. This doesn't help.
So, I can't use the watch as a phone with this switch set to off, if I answer a call with the watch it will say 'talk on the phone' which kind of defeats the whole purpose of having this watch and paying extra for the service to the watch.
I believe this issue started because of an update to the watch or the phone.
Am I the only one having this problem? Is anyone else experiencing this? Thanks for your reply.
Solved! Go to Solution.
I am having the same issue. When my watch 4 classic connected for calls, no audio output available for my car player.
The issue is gone now that my phone was upgraded to One UI 5.1.