So sorry for the late reply. I have MIC but cannot target the billboards to see their info. Clicking on the billboard just selects whatever is behind it. So I had to disable/enable all the mods to see which ones are causing these issues. I've narrowed it down to two mods:
1. Dense Nordic Forests
2. Reduce Reach Trees
The first mod adds more trees to Skyrim, the second one removes most of base game vanilla reach trees to make the region look more barren. Disabling these mods removes all the billboard issues, but I really want to use these two mods, so how would I go about trying to fix the billboards. With or without DyndoLOD these billboards show up in the game, so untill I can remove them, there is no point on running DyndoLOD again. Any help is appreaciated!