Thank you.
Where would I find this with a Verizon FIOS router? (Yes, I am looking into a new router that is more configurable)
The only thing I can find under any of the HomePods and Minis is Phy Rate / Modulation Rate
72 Mbps. Nothing about TxRate in the manual, and an internet search didn't turn up anything other than upload and download speeds.
There does not seem to be any way to keep them in the 5GHz bands, but even when all the devices are connected there they still go out of sync. For example, while I was typing this, the stereo pair closest to me, and about 8' from the router, just went badly out of sync, with one several seconds behind the other. Usually the stereo pairs stay in sync, while the ones in other rooms are ahead or behind. This is a 100,000 square foot house, so range is rarely an issue.
The only way to force them to stay on 5GHz is to give the bands different names. I have a few devices that only run on 2.5GHz, and are a massive PITA to configure, so I'd rather not do that.