Add M9 on existing network normally, after this, change M9 to main Deco and put M9 as main router. Change M5 with M9 after this. All settings on M5 will be used by M9.

See information here https://community.tp-link.com/en/home/forum/topic/163152

First, sorry for portuguese version off the app. QUARTO FRENTE is a Deco Unit 2 @ home with backhaul, "Fonte de Sinal" Escritorio with out wifi signal meter, with this when backhaul working. And how...

Wi-Fi SON (Qualcomm Features on IPQ4019) is enable on Deco series?

LucasMelk wrote This beta firmware can be flash in Deco M5 v1? i flash 36613 / 20190529 into V1 and no issues. Network stable and fast. 4 Nodes at same network.

@Kevin_Z i can use build m5_20190529 on M5 V1?