Ledvance and Silvercrest smart plugs difficult with Homey

I have difficulies to make my smart plugs from Ledvance and Silvercrest work with Homey. Most times it fails to make the connection with Homey. The same plugs work with Philips Hue without problems. With Hue I can make the connection in a few seconds.
I want to switch to one network (Homey or Hue). My lamps and plug from Klikaan/klikuit and Ikea work with Homey without problems.
Who can give advice?