Echo, Sonos Connect, Yamaha A/V receiver, Harmony volume control issue

Current setup: Harmony Elite remote (and associated Hub), Sonos Connect, Yamaha RX-A760 A/V receiver amplifying (playing to) non-Sonos speakers & subwoofer, Amazon Echo, & other devices not related to this issue (ie. LG OLED65B6P TV, Samsung Blu-ray player, Apple TV 4K, Wink Hub 2, Philips Hue Hub 2, Orbi router, Rasberri Pi, Google Chromecast). On the Harmony Elite I have an activity named “Sonos”. I have another activity named “DirecTv Now”, and another named “Blu-ray”, etc. etc. I have the Harmony skill as well as the Sonos skill enabled in the Echo app. When I say “Alexa, turn on DirecTv Now”, Echo (Alexa) triggers the Harmony Elite and starts the “DirecTV Now” activity (LG TV: power on, LG TV: input HDMI 1, Yamaha A/V receiver: Power On, Yamaha A/V receiver: input HDMI 1 (Apple TV). The system is now ready to use the “DirecTv Now” activity on the Harmony remote (DirecTv Now app is provided from the Apple TV). If I then say “Alexa, volume up” the Harmony remote is again triggered and the “Volume Up” command is sent from the Harmony remote to the A/V receiver (due to volume punch through to A/V receiver in Harmony program) and the A/V receiver volume increases. Perfect!!! In the echo app I created a group called “Family Room”. In the “Family Room” group of the Echo app I have the Sonos Connect selected as the “Preferred speaker”. When I say “Alexa, Play Music” for example, Echo plays Spotify (my preferred music source in the Echo app) as intended through the Sonos Connect (not through the Echo speakers) which in turn is connected to the Yamaha A/V receiver which in turn is connected to my non-Sonos speakers and music is heard in the Family Room. Perfect!!! Now, if I say “ Alexa, turn up the volume”, or “Alexa, volume up” or a few other similar commands, Echo will attempt to turn up the volume in the Sonos Connect which results in no volume increase. The Sonos Connect has volume output set as “Fixed” in the Sonos app because I am using an A/V receiver for amplification/volume, so the volume does not increase. ****What I want is for the volume command to “punch through” to the Harmony Elite “Volume Up” command which increases the A/V receiver volume, just as it does when I am in the “DirecTv Now” activity of the Harmony remote.*** As a temporary workaround, I enabled the Yamaha MusicCast skill in the Echo. I can now say “Alexa, ask MusicCast to turn up the volume in the Family Room” and she will increase the volume on the Yamaha A/V receiver. I would much rather say “Alexa, turn up the volume” just as I do with my other activities (ie. DirecTv Now) for consistency with voice commands. Piece of cake....right???