Unfortunately the only way I’ve been able to get my HomePod Minis to work reliably is to disable the 5Ghz band completely and only have 2.4 — even when they’re in the same room as the AP!
Having two separate SSIDs and joining them to the 2.4GHz SSID also works, but it’s kind of a pain and you lose certain functionality if they aren’t on the same SSID as your iPhone.
Having two separate SSIDs and joining them to the 2.4GHz SSID also works, but it’s kind of a pain and you lose certain functionality if they aren’t on the same SSID as your iPhone.