Shelly S MTR niet te koppelen met HomeyPro

Did you miss the instructions in the Shelly app topic?

When you’ve added the plug as WiFi plug to the Shelly phone app, you shouldn’t push buttons anylonger. Then you’ll just reset it!

For some reason you don’t specify which Pro and which MTR plug model you’re using, but with the Pro 2023 & plug S MTR Gen3 you can also use Matter, so you should be able to add it as a Matter device.