Shoebacca slides with # on bottom?

I have received 5-10 pair of slides direct through adidas, this is the first pair I've ordered from a reseller. These are a 3Y for my 6yr old. None of his other pair or my adult pair have a # on the bottom. I looked this # up and found the toddler slides in the resin with them. Maybe this is just how older models were? I don't have any other slides with a number on the bottom 🤷‍♂️

2020 manufacture date.

I finally got my size tephra (14.5) from them and ordered several other pairs of foams and slides for my 6yr old.