One Velux Windows not more connected

Hello everyone,
I have installed the Homekit and all windows and shutters can be controlled with it. After about a month, one window (“office”) in HA no longer works and can no longer be addressed. With the Velux remote control it works without any problems (windows and shutters). The entire Velux system is linked via Velux Gateway Netatmo.
As this works without any problems via the Velux remote control, it must be due to HA.
Now to the question: How can I delete the identity cover:velux_window_roof_windows? In the print screen the “Delete” is gray, cannot be deleted. Or do I have to uninstall and reinstall the whole Homekit? Does anyone have a system like this in use?
Many thanks for your help!!!