ATT Interent Air Compatibility with Blink Sync 2 module and other 2.4GHz wifi products?

I have had my system for a week now, replacing my old ATT Internet 10 router.  It set up easily enough and delivers MUCH higher speeds.  I have been working through compatibility issues and learned today that my pre-existing Amplifi Mesh Network works with the Air router via ethernet connection, but degrades the functionality speed to 2.4 GHz for everything that connects into the Mesh network.  Internet Air permits only one computer to connect via wifi on the primary network, and refuses all other attempts with the message of "incorrect password".  However, it will accept those other devices into the wifi network via the guest network at the lower speed.  This also reduces the effectiveness of the mesh web network.  My Blink security network which requires 2.4GHz connection (Blink Sync Module Gen. 1), but the Sync module fails upon attempts to connect.

The following internet add-ons are currently connecting with success:  DirecTV Connected Home Adapter DCAU1RO-01 (via ethernet, EPSON ET3760 (via 2.4GHz wifi), Nest Gen 1 wifi thermostat, iPhone 14 Pro, iPhone 14 Pro Max, Apple Mac Book M1 Pro 2, Apple iMac M1 2, Apple iPad Pro.

My SunnyBoy Solar equipment previously connected with the Amplifi Mesh network via a NetGear Extender via both 5GHz and 2.4GHZ radio antenna.  I have not yet been able to establish a connection with this equipment either.

I have been on ATT Tech Support multiple times and only today did I establish the deficiency between the Amplifi Mesh Web network.  I have disconnected the Amplifi and have reverted back to ONLY the wifi supplied by the ATT Internet Air router.  The most recent tech support agent recommended adding the All-Fi Booster (CGW450) which is supplied by ATT for an additional $10/month.  It is the only compatible wifi extender identified by ATT on their Internet Air website.  Has anyone found any other successful compatible mesh web appliances other than the All-Fi Booster?

Has anyone deployed the All-Fi Booster (CGW450) or had any success with any other wifi extenders on the market?  Has anyone identified any other deficient or successful compatibilities?