RBR50 Mesh Network does not connect to my legacy devices (GMG Grill WIFI 2.4Ghz)

RBR50 V2.3.5.30 Serial # 5LY18A510FEC8

RBS50 V2.5.1.16 Serial # 5LN18A570FEC8

I have a GMGGrill which I cannot connect to the network, GMG state that the Wifi must only operate at 2.4Ghz. Since the Orbi transmitts both 2.4 & 5Ghz simultaniously the GMG client will not connect to the Orbi network. I am looking for a low tech solution as I donot feel confident in changing the Routers firmware with telenet client?

Is the a Wifi extender that would work by transmitting at 2.4Ghz?

Any help would be appreciated - Love my Orbi - Sorry Netgear did not see fit to add a software switch to cover issues like this.

Fitbits Aria scales has the same issue.