Banner alerts but not always beeps on course navigation

I’ve created several courses in Garmin Connect (web version) so that on newer/unfamiliar routes I can get alerts at turn offs, turn arounds, etc. This functionality is a large part of why I upgraded to the 245. Initially when I first purchased the watch (whatever software version was in play in late May in the US) i got a beep alert when the lower banner with upcoming turn (or off-course warning) appeared on the display. 

For the last couple months, however, the beep alerts don’t accompany the banner alerts until 30-45 minutes into the run. This renders the feature rather useless unless you already know the route well enough to know about when to check the display for a turn alert. I’d rather not be staring at the watch like this even when I do have a vague sense of where I’m switching up.

This happens in both run and walk mode, it happens whether or not I have other competing alerts set, etc. The same routes that use to give me audio alerts as well as the visual alerts early on also have the issue. I don’t think it’s GPS related because, again, i am getting turn alerts, just silently. Please help.