First Alert Zcombo Wont Discover

I just bought some Furst Alert Zcombo units from Costco. Production date 2022-Feb and they’re all plain “ZCOMBO” on the back. I can’t get them to discover from my Synology run HA instance using an Aeotec Gen5 stick.

They pair fine to my Hubitat (which I’m retiring soon).

I’ve read as much as I can here in forums but haven’t figured out what I can do to get these to pair. My inclusion process from HA just times out, whereas the Hubitat is able to find a device after maybe 3-4 seconds every time.

I’ve tried fresh devices (out of the box), I’ve tried hardware reset in the First Alert, I’ve tried Exclude on the first alert (which isn’t super meaningful as AFAIK). Not sure what else to do?

Thx

Did you ever come right with this issue?