Phonak Audeo Lumity losing charge quickly

I have a pair of Phonak Audeo Lumity hearing aids, which I love. They are 1.5 years old.

I think the battery in the right hearing aid is beginning to fail. This began a few days ago. I have reset the charger, and the hearing aid itself (by holding down the “off” button for at least 15 seconds). Both hearing aids come out of the charger at 99%, but the right one begins losing charge immediately, dropping to 80% within 30 minutes and continuing rapidly to decline. This is without any kind of bluetooth use, phone use, etc. And soon, maybe just a few hours of use, the right hearing aid battery has lost almost all of its charge. I’ve contacted Phonak and my audiologist, but I think they need to have the batteries replaced under warranty already.