Mesh DECO M5 with 4x amp:connect... not working anymore (working fine under old setup with 3  Extreme)

Hi guys,
I need serious help after replacing my 3  extreme for 6x TP-Link DECO M5
impossible to get any music through the DECO M5
here's my original setup
4x Sonos AMP:CONNECT
3x AirPort Extreme (tower version)
never connected any CAT5 to any of my 4x AMP:CONNECT
all music was perfectly streamed only over wifi form any od all my  devices without any issues for years
I decide to replace the 3x older Airport for 6x DECO M5
1x DECO is acting as a router & I have connected a network switch for network port expansion, NAS, iMac....
the only difference is my new wifi system (much better over my 6000sq/ft)
but now after totally reset my 4x AMP:CONNECT I still not able to stream anything on it
as a test I decided to reconnect 1x older AirPort Extreme directly to my network switch (who is connected directly to the new DECO). BINGO !!! music is back !!! but I have to create a different wifi network, 1x for DECO, 1x for Airport
Why I can stream through the airport connected the the new DECO vis a network switch but impossible if I remove the Airport... I LOST !
and I cannot at any location run a CAT5 to any of my 4X AMP:CONNECT, it has to be only over wifi
Thank you