Arms Racer achievement not unlocking

[TTVJamminJammie]

I personally don't know if I have some kind of obscure weapon hiding, but after completing all dlc, skrimishes, mission, and combed for all aces. I believe that it could be either The Two Valkyria dlc, which I couldn't find the ace locations, or the reward weapons, with some of them being so damn obscure, it's just ridiculous. If anyone could give me a list of reward weapons, or possibly give me ace locations of The Two Valkyria, (which did feel short), that would be wonderful.

[Lanzagranadas]

The Two Valkyria doesn't matter. None of the DLC weapons are required for the Arm Racer achievement and, as far as i know, that DLC in particular doesn't even have Aces.

You can find the weapon list in this guide:

https://steamcommunity.com/sharedfiles/filedetails/?id=1528417888

Reward weapons you might have missed can be purchased using Renown at the Infirmary. But they're still random within weapon rank so better save your game before trying, then if you didn't get what you wanted reload so your Renown doesn't go to waste.

[RAID Noir]

Also recheck every Ace drop in your squad stories. Just completed 100% earlier