HomeKit won't allow me to add accessories

Hello, I'm stuck.

I keep getting the same error message. I have numerous accessories that work fine on HomeKit (Logitech doorbell, eve indoor camera). Then tried to add Eve outdoor cam and kept getting the massage attached. Also tried to add another TP smart switch with same effect. Actions taken:

• Disable 5G
• Reset router Linksys Velop (3 times). Also talked to support.
• Consulted Eve support (they said nothing they can do)
• Confirmed all hardware firmware up to date.
• Disabled homekit on router (recommended by Eve Support)

What am I doing wrong?