WatchOS 26 workout announcements not working

After having updated my watch series 7 to WatchOS 26 I am seeing few issues...

During a core workout I set the watch to announce the workout time every 30 seconds. I listen to music on AirPod Pro 2 while working out. The time announcements start reasonably OK, although there's a long wait with the music muted (about 5 seconds) and a "pop" in each ear before the announcement. After a little time (last week it was 20 minutes, this morning after 2 minutes) the announcements stop but the haptic "tap" still works at each 30 second boundary. If I stop and restart the workout (with the 2-button "pause" press) the "Workout Paused/Resumed" announcement works and the 30 second announcements sometimes come back. This seems to be a bit of a lottery. This morning the first "pause/resume" sequence brought back the time announcements but they failed after a few minutes and the second attempt at "pausing/resuming" made no difference.

Anyone else seen this behaviour, or have an idea (that doesn't include all the normal "restart/reset" moves) that may solve this issue?