Zooz Zen 24 dimmer switch

I’m having LOTS of problems with two of these switches, while two are working fine.
One works, but keeps displaying “ERROR: Unable to get any information on node…” in the UI7 interface.
The other partially paired, so I deleted it and tried the process again, and now it won’t do anything. I followed the factory reset procedure per the manufacturer, and it won’t reset, won’t pair.
Like I said, I’ve got four of these, and first two I installed work fine. The last two, not so much. Anything ideas?
Thanks for whatever help anyone can provide.