Choppy Audio...Ring 2

Well working on our second Ring 2 doorbell. First unit experienced choppy audio from both mic and speaker on phones, Echo devices, and computer. Contacted Ring support went throught all the usual troubleshooting which ended with Ring sending out a replacement which we installed this week. Sure enough, second unit is experiencing same issues. We subsequently installed a Chime Pro which really improved the signal strength, router at 46 RSSI and Chime Pro at 49. We also replaced the aging doorbell transformer which appears to have improved the battery charging but STILL very poor audio. We have explored possible interference from other devices by disconnecting each and testing Ring audio, no luck. If anyone has any other suggestions it would really be greatly appreaciated !