Hub v3 in Denmark - slow execution

For 2 months ago I bought a ST hub v3 in england, but to be able to activate it in Denmark with STSC, I had to create a Samsung Account as an American, through VPN. Everything seems ok, but routines, scenes and bulbs turn on and off quite slowly, up to several seconds. A scene may well be 30 sec. to be completely finished.
I have now switched to the ST Classic app, which is somewhat better, but it is still slow. I have 75 zigbee / z-wave devices in the network. Most ikea bulbs and Danfoss thermostats.

Can the speed problem be due to the US account and can I change it to the EU?
I have checked my 2.4GHz Wifi and have turned everything off on channels 10-13.

Appreciate some hints, otherwise I’m super happy for my ST :slight_smile: