bought one HS300 in april and was very happy with it

bought two more on dec 10th and set one up immediately and had it working for 5 days without issue, connected contuinously

I try to set up the other one a few days later and while setting up it asks me to update, I do so, I aslo update the other strip so everything is up to date

it connects, then disconnects, I now have it in a room in the kasa app and it looses connectivity to it every 20 second, and then reconnects after 10 seconds
and repeats

I have repeatedly reset the units, changed wifi to different routers, and tried all other things available

neither one can be accessed by third part apps, regardless of setting for 3rd party access
(i get

Unable to authenticate: Device response did not match our challenge on ip 192.168.0.XX, check that your e-mail and password (both case-sensitive) are correct.

even after I reset my password and restart Home Asssistant
)

how can i troubleshoot? how can I get them to stay conencted for more than 30 seconds? how can i rollback