I first tried without mods, and after experiencing the same bug I verified my files. Then tried with, and without mods, and it was as you said: My game files had some problems.
I customize lots of stuff on xml files, so I wasn't surprised with the verification of game files, but the fact that something affected the game map features was unexpected to me.

Its all well, and done now. Thank you. And I gotta say, its a good map. Make harder maps please, but stick to CQB. I hate open field maps. This one was fine, but I'd rather maps where we travel indoors.

That's strange. I used to have that bug, but it was fixed whenever I updated the map for CIA. I just checked and for me, the garage doors work perfectly fine. Not 100% sure what the cause is - I'll try uploading the map again to see if it gets fixed.

If I'm not mistaken, that gate was bugged in earlier builds of the game and was see-through but it was fixed a long time ago. It might be possible your files or the files on the steam workshop are outdated or didn't update properly.

If it still ends up being a problem, there is a sham fix to add a manual visual blocker to the garage door, but the problem with that method is you still can't see through it even after you blow it open. I used to use that fix on older versions of the map prior to the gate being fixed by the devs.

I don't know if it's intended (Though it shouldn't be they are suppose to be solid garage doors.) but the garage doors facing each other in the bottom right buildings are see-through, and I found that out by an RPG hitting the walls in the left (bottom-middle) garage.

This is how it looks like: https://i.imgur.com/3v6tiiP.png

And I have no idea why the RPG dude decided to shoot at nothing. Nobody died from the explosion but we lost our cover which were the walls :D.

Also, on the note of CIA:

I tried doing CIA but I found out very quickly that using CIA on a clear hostiles map with 50 some bad guys is a very, very bad idea. I have updated the map with suspicious and restricted areas but I'm liable to change them again, not happy with them in their current state.

Yeah, I had similar issues to what you see here attempting to do a number of the older maps with longer range engagements. It took me about 10 tries knowing the location of every single enemy on the map in order to complete it, and even then 3/5 assaulters were red injured and I had no utility left at the end of it (except one smoke grenade lmao).

My only real three tips are bring AT-4s to breach open buildings you can't get close enough to clear without exposing yourself. The Marksman needs a good long-range sniper to take out the guys on the barricade in one or two shots, but also the ability to engage closer targets too. He requires a lot of micro. The Grenadier can be helpful to open up doors or windows from a distance (generally safer) but needs someone else to actually do the shooting once everything is opened up.

I tried to one-up the challenge by not changing the load out, but it has proven impossible for me, after around a total of around 20 retries I had to leave for my university classes.
I see what you were saying about the nades update, it is IMPOSSIBLE to clear the lower half-second building without breaching into the fisrt building and flashbanging from the window, however, it is impossible to make a wall off smokes to get to the end of the map, or else you'd have 0 utilities left, when before you could do it with mabe 2 smoke and one lucky sprint (it took me some tries to see them because i was smoking the street to split the stack anyway).
This evening I'll go back to it (maybe as CIA), I wont take it as a LOSS (restarts doesn't count, lol)
But it is really well thought, you can see the map in a way that you know where to expect heavier resistance, smokes are a must, and i'm not gonna save all civilians when i get back, they are so stupid it HURTS

That guy from youtube