I have an insignia Roku TV, and have used the private listening feature for iOS on a Bluetooth headset for months without any issue. One day, a few weeks ago, the audio feed started popping in and out and stuttering, to a point where it's totally unusable.

I have tried everything-- restarting the system, deleting and reinstalling the app, etc. I am running the most recent Roku software, and have tried with various wired and wireless headphones. My wifi is 100Mbs/Second. Very disapapointing as I used to use this feature all the time. any ideas?

Roku programmers are on vacation.  That is unfortunate.