@Yannie Thanks. Yes, I think this is what I was looking for! I haven't tried the checkbox "profile overrides". I have also found it now in the user guide. (I think I've overlooked yesterday).

I want to set up Port Mirroring via Omada hardware Controller OC200, but I can nowhere find how to do it. If I want to go directly to the web interface of the switch, I got the message that it is not...