Mirroring on SwOS - CSS326

Dear Community,

I have an issue with traffic mirroring on Mikrotik CSS326. Here is specific problem: When you mirror traffic from a port with is configured as a designated specific VLAN - traffic is mirrored as expected, if you want to mirror traffic from a port which acts as a trunk port (i.e. connected to a router port which has virtual sub-interfaces) this traffic is not mirrored. Is there any solution to make mirroring working on Mikrotik with trunk ports?

Thanks in advance!

Been a while since I was mirroring traffic on either of my CSS326 switches, but when I was doing some testing a couple years ago, mirroring traffic from a trunk port was working fine (that was my specific test). What version of SwOS are you using?