-FIXED-
Well I found out my problem. It was the Personal Arsenal mod by "Drakeziel." I guess either it hasn't been updated according to that arsenal update arma 3 recently had or it broke it or whatever. I disabled that arsenal and tried out this other one called Personal Arsenal (XLA) by "Seven" which is based on Drakeziel's mod. This one works perfectly and all the attachments are back, only difference is this mod's scroll list is a little shorter. Good luck to you figuring out yours, hopefully this is the case for you aswell.

I guess the map loading thing is just lag. I loaded a game and sat around for a few minutes and after like 5 or so the outposts and seaports started showing up again, as if its loading very late. Attachments still gone for every gun, I feel you it really sucks I've wanted to play but its so lame without the attachments.

Are you getting this missing map marker problem too? Or is that just me? Looking for the issue is when I discovered my attachments were missing and still can't tell if these two problems are related or not.

I just made an account since this is the only place I see the same problem.
A few days ago, pretty much when this thread was made, I loaded my scenario and on the map every airbase, sea port, factory, and outpost's markers on the map were missing, along with the garrison and flagpole at those locations, yet if I fast travel and click around the area I remember the marker being, it will take me there, the place will just be flagless and empty, even for my multiplayer scenario I loaded up just to check markers are missing aswell. The only markers on the map that exist are the town markers. I started disabling and re-enabling mods and while I just tested a bunch of things I found that every attachment is missing for every gun, vanilla weapons, RHS weapons, SMA weapons, everything, and I'm using personal arsenal to see them all.
Through disabling some or all mods the attachments are still missing for every gun. If I load up my persistent save of my previous game, my gun in my hands still has the attachments on it, but when I'm in the arsenal it shows <empty>. As for the marker part, I've found only that loading up my save, the markers are missing, but if I start a fresh game, the markers appear. I guess I'm cool with starting a fresh game to fix the markers, but I can't get the attachments to appear.