Hi CaptTom - I also have three Honeywell WIFI thermostats, but only one is showing up in HA for me. Did you have to modify anything within HA in order to have all 3 be available? Much appreciated!
There’s a known bug with the 8.x version of HA which causes exactly this symptom; only one Honeywell thermostat shows up in HA. I posted about it here, among other places: