I can configure your network properly with a static IP and set up NAT/Firewall over TeamViewer for a small fee, payable via PayPal.
For reference, I've spent more than a decade troubleshooting RA2/YR bugs and problems for players across the world.
I see from your screenshots that the cycle only changes the brightness, but did you know you can also change the colour of lighting with triggers for red, green and blue, to create sunrise and sunset colours.
I had to restart the campaign because of this and next time it wasn't doing it.
Try to play from a previous mission to reach this one again, or re-install the game, and check out community patches.
Use trigger with the action "do damage at waypoint...".
3 waypoints directly under the bridge are enough, for preview rendering you should set the tiles manually.
Updated Final Alert 2 downloads in the first post with the new Final Alert 2 v2.02b based on the released source code.
New re-arranged menu toolbar.
New larger toolbar icons.
Added status bar features.
The map terrain editor's background colour is set to dark grey.
The Map visible area bounds and playable area bounds are displayed separately.
Full changes list on Github: https://github.com/CnC-RaVaGe/YRR_Mission_Editor