Yes, those are the right parameters to set.
P21 is the AC Power Type
Use to select whether or not your switch is wired in a neutral or non-neutral setup
0 = Non-Neutral, 1 = Neutral
P21 should be set to one or the other, depending on your wiring.
P22 is the Switch Type
Use to select what scenario your switch is wired – single pole, multi-switch w/dumb (existing) switch, or multi-switch w/auxiliary (add-on) switch
0 = Single-Pole,
1 = Multi-Switch Setup (Dumb/Existing)
2 = Multi-Switch Setup (Aux/Add-On)
When you are using an Aux switch, P22 should be to “2”, which is the “Momentary” setting that is correct for an Aux switch.
If P22 is set correctly, can you explain or draw how you have it wired? If we don’t get it with that we’ll ask for pics of your boxes.
I understand you’re setting the parameters at the switch. Which hub are you using? I’d confirm/set the parameters there.
Red Dimmer Manual: