R8/R6/R4 Stereo connection issues

[Sierra588]

Any R8/R6/R4 owners out there with stereo connection issues recently?

We have 2021 R8 Suft (Garmin 8610 & Fusion RA670 head unit) works for 20-45 minutes after staring and looses connection. Once connection is lost we aren't able to reconnect with normal iPhone or other phones. I purchased boat new and have not had issues like this in the past.

Recent actions to resolve....
-updated software on Garmins (running v35.30 now)
-updated software on Fusion (running v6.20 now)
-updated iOS on iPhone(s) (running 17.5.1)
-Reset Fusion to factory default and issue still exists.

Perplexed on the issue and appreciate any suggestions the forum can share.

Thanks