Newifi-D2, traffic mirroring

Hello,

for the past few days I have been struggling with setting up traffic mirroring. I have a Newifi D2 router. What I noticed strange is that when using tcpdump on "br-lan" interface I can't see full packets where for comparison tcpdump on lan(X) interface works fine - full packet is visible.

some example pcap files where I was using command "curl testmyids.com" on br-lan and lan3 interface - where on lan3 full packet is visible.

https://www.dropbox.com/scl/fo/eeqj6mn7el52grtazrmi6/AGZJ1qSVI_fX7NXmIT3r5lI?rlkey=5d136pik0iw1zunek51piencu&st=kdt7c6ex&dl=0

Thanks.