Plantronics Voyager Legend Headset Disconnecting/Reconnecting Midcall with iPhone XR

My wife and I just switched from iPhone 7 devices running iOS 12 to iPhone XR devices running iOS 12.4.1 (the latest version). We both also use a Plantronics Voyager Legend headset, which is an older headset but still one of the best on the market imho.

With the iPhone 7 devices, we never had any issues. With the iPhone XR, you will actually hear the headset disconnecting then reconnecting in the middle of a call (three tones on Plantronics). More of a nuisance than anything else but I want to get this issue fixed.

So to summarize:

1) Worked fine with iPhone 7 running current iOS

2) Issue started when we migrated to iPhone XR running current iOS

3) Yes we have rebooted.

4) Yes we have restored both network and all settings.

5) We are both using an Incipio NGP case, which is a very thin hardened rubber case. Same case as the iPhone 7s, slightly different material but I can't believe that that would be the issue.

6) Calls are being made in very close proximity between XR and Plantronics headset.

7) Plantronics headset shows as connected via Bluetooth on XR whenever headset is powered on.

I have my own separate but related issue where the iPhone 7/Plantronics combination would start a call out on the headset, but when it connected it would switch over to the iPhone. I don't think that I am still having that same issue with the XR but I am not sure.

There is an updated version of the Plantronics Voyager headset but it's pricey and I can't believe that switching phones with the same iOS version would put the fault of all of this on the headset, but I am up for suggestions.

Thanks in advance.