Router model: TP-Link Archer AX11000

Latest FW version: 1.1.1 Build 20200716 rel.84595

This issue has been really discounting the user experience on the connected Google devices. Router setup with all 3 bands enabled within different SSID, no guest network, and have a total of close to 40 devices connected all time. Most of the smart switches and lights and connected to the 2.4GHz band and about 10ish google devices (home mini/max, nest hub max, thermostat, outdoor cams, doorbell, yale lock) spread evenly across 2.4G/5G-1/5G-2 bands. My Google home app are not able to connect to all Google home devices no matter which band my phone is connected to, and prompts my phone to connect to Wifi to Cast which I'm obviously connected to my wifi. Connectitivy on all the Google home devices are fine as they all can work individually, but lack of Google home app discovery means I can not modify the setups and cast video/play spotify thru my phone. I believe this is a router or router setup issue as everytime I reset/reboot the router and modem, it will work for a day and then stopped working again. 

Any one have similar experience and can share the resolution? Love this router at the begining but the google home devices connection issue has been bugging me a lot lately. Will all the Google home device being on the one 5G band be any help?

Thanks in advance.