This is an older video so I'm not sure if you'll see this but I just finished installing OPNsense via XCP-NG hypervisor on a M920x with a 4 port Intel NIC. My question since you're unable to select "custom" for the filtering with the free license, are you able to manually select the apps to block on that other screen? For example, I'm looking to block Tik-Tok from my home network, would Sensei via free license support this?
To my knowledge, you should be able to see the traffic under the connections tab and select the block button on the far right side of the listing but I've had to wait to "see" the traffic go across to catch it and do so.