Crop top knit top

This is knit from like a nylon type fabric making it look sleek and shiny so it looks has a dressier look. One of the ties in the back started to come undone in the wash when I washed it to sell it. Before that it was new with the tag but I thought it would be better to wash. I tied it up so it won’t pull and it’s just the tie that ties behind your back so it’s not a major flaw. You can’t even tell. Size S/M