Hello.
I need your help. I'm trying to configure Trunk with Vlan1 and Vlan2 between two managed device:
First is Netgear R7800 with OpenWRT 18.06.1
Second - Mikrotik RB260GS with SwOS 2.8
This is the screenshot of OpenWRT with VLAN configuration. Now LAN1 is not the trunk. To make it a trunk I configure LAN1 as Tagged both Vlans. This is the screenshots of RB260GS:
I need port IPTV as VLAN2 and other ports as VLAN1. Port named uplink is a trunk.
VLAN and VLANS Unfortunately, this does not work. I can't reach any device connected to the ports named Denon, x9s or IPTV.
Where is the mistake?
Please help me solve this.

Good question, just getting into the settings myself. Its a different beast that iss for sure.
One thing I would do is ensure i have not frigged with the PORT FORWARDING PAGE (ensure the defaults are still there).

Your VLANS table looks correct!

For the VLAN Table.
For all VLAN MODE entries use enabled except IPTV which is correctly sent to strict.
FOR Egress
Vlan header settings should be leave as is for all except always strip for IPTV, this assumes IPTV does not tag or understand tags.

Give it a try and see if there is progress.