All Homey devices in Google Home (GH) are offline after linking

[Rrrr]

Update: I suspect my (unifi USG) network settings because with my old HP2016 and only one virtual button I have the same issue:

• Linking Homey to Google Home succeeds 1 of 5 times. Sometimes devices are linked, but offline
• Unlinking Home from Google Home succeeds 1 of 5 times

Upon linking

1. Google home says: “Homey is linked” followed by

• When I use an iPhone: “Something Went Wrong”
• WHen use an Android phone: “Could not reach Homey. Please try again.”

I would be grateful if anyone with a Unifi USG router could post his settings below.

Here three screenshots of my current settings:

1. Settings/Network overview
2. Settings/Network, network selected
3. Settings/Firewall overview (my port forwarding is disabled)