nifty knitting problem - Can't add items to wardrobe

Hey guys,

maybe someone here knows a solution to this:
I just got the "nifty knitting" add-on some weeks ago. After playing it for a while I notice that I only can add on version of a knitted clothing to my wardrobe. 

Like .. I can add the red socks but not the blue one of the same type. At first I thought I did something wrong, and tried different things, but this is with all clothing Items!

I made a new game ... didn't work

I did repair my data ... didn't work

I have no mods installed or anything of that ... 

I have most of the expension packs and Item packs so far ... and I have no Idea why this is happening. Takes the fun from this feature for me so far. 

Thanks in advance