Not sure how long this has been a thing, but I notices when I bought the AMX 13 57 that it didnt show up in my carousel in game. At first I though it was a WG delay, but with a little fiddling, it turns out that if I use the MOD that lets you have 2,3,4 rows in the carousel, that for some reason that one tank (maybe others but I never noticed) does not show up. Doesnt matter what filters are on/off the AMX 13 57 just does not display. Once I disable that mod, the tank appears.
WEIRD