Some Addon EUP invisible, please help!

Hello,
I recently added some addon EUP to my FiveM server, what I mean by addon eup is that I make my own EUP DLC Type using YMT editor and make it a separate resource, I followed a FiveM tutorial for this.
I have quite a few items of clothing ranging from shirts, to pants, to masks to duty belts and most work, but some of these pieces of clothing I have been adding seem to be invisible both when they are addon in my pack as well as when I test them by replacing a normal EUP slot.

Can anybody suggest what may be wrong? the main items of clothing which are invisible as I speak are one pants model and two hat models, the slots show up as an additional slot in vMenu but when you try to put them on they are just not visible as if nothing is there.

Cheers in advance!