Moving Box Unlock Bugged?

[y0rch1]

Yasterday I went for my last unlock which was surprisingly the moving box, I thought I already did use Pandoras Box on dark room in my hundreds of hours of Isaac but maybe it just slipped past me, but when I used it the achievemnt didnt pop up, I thought it was due to a weird interaction with school bag so I did the same thing today, after hours of playing finally managed to find PB and make it to dark room only for it to not work again.
I have no mods and Im playing on PC obviously, I really would appreciate if someone could tell me what Im doing wrong. I checked if the achievement 366 is locked (which it is) my past run and this one once I used it. Its the only unlock left and Im going insane.

https://steamcommunity.com/sharedfiles/filedetails/?id=3375223966

[y0rch1]

Im kind of regarded, In case someone else has the same problem I will leave this posted. It is because I had the Blue Key trinket in both runs somehow, which sounds crazy thinking about it. Blue key skips the Pandora's Box effect when used and instead spawns 6 items. But what are the odds tho?

[archidictus]

I just had the same thing happen last night. Blue Key with Pandora's Box to dark room, no achievement. That annoys me. It's a long one, but not really a hard one to get :\