If the Garmin Connect app is not running in the foreground, audio prompts during an activity are not to be heard anymore.
Only with an open Connect app, audio prompts can be heard.
That's not how it should be. Nobody has the Connect app open and activated during an activity.
(Android Samsung S25 Ultra, Connect app v 5.17.1, connected to Forerunner 955, with Google TTS activated)
While it all is about audio prompts, that problem is new and was introduced with the GC 5.17.1. No audio prompts unless GC is running in the foreground (= phone screen on and displaying GC).
Similar threads throughout the forum, including this one with a response from Garmin - Audio prompts
I am sorry to hear you are having trouble with the audio prompts. There is a potential…
5.17.2 The first impression was that the voice alerts for starting, stopping, and looping had returned. However, after a few attempts, the alerts were no longer present or required the app to be opened…
There is the 5.17.2 GC update available.
It seems to solve this particular problem. I did a very quick test, just started, paused, resumed then stopped and deleted the activity (indoor cycling if that matters) and I got audio start/pause/resume/stop messages even though my phone had all apps closed, the screen was black and locked for over 0.5h.
EDITED (23 hours later):
It didn't worked for me today 
.
