SmartThings not registering devices under new location

I’ve been using SmartThings for one Samsung air conditioner (AR12NXPD) for over a year without any major issues.
I’m now trying to add two more identical units at a new location (different building) and I cannot find any way to get them to register or connect via Wifi…tried every way possible and get either one of following error codes after it spends it’s sweet time searching in AP mode (error 05-300 and 11-001)
The model shows up under Thermia brand and not under supported Samsung devices, but I’ve tried connecting with both brands.