I’ve long thought the problem was more with the app than my phone or hearing aids. Uninstalling/reinstalling the app did no good. Here’s what finally seemed to clear the cobwebs:
Open settings
Scroll down and select APPs
Tap the See all options at the bottom
Tap the app name whose app cache you want to clear (Phonak)
Tape Storage and cache (2 images)
Select Clear cache
Tap Clear storage to clear data and cache.
Everything has been working as advertised now for 5 days.
Thanks for all the advice.