How to reset/delete Entity-button setting

I tried to delete the setting of the POWER-button of an entity by clicking on „Reset to default“:

Setting then is removed :

When using the button, the button is still sending the code which was defined before.

How can I really delete a setting?

Is the button still mapped if you reload the page? Delete your browser cache and use the ip address to access the configurator to prevent connection dropouts to the remote.

I am using IP-address only.

Of course strange that the webbrowser is showing the right settings, but the remote does not consider it. Why shall deleting browser-cache help?

Now I just opened the web-configuration in an incognito-window - without clearing cache etc. - and configuration is shown as in normal browser-window: no action assigned. I haven’t done now any further configuration, just viewing via browser the settings, but this morning suddenly the Power-button is not sending any command anymore - as intended.

Really strange.