(Variations) big problem

Hello,
after upgrade woocommerse to 3.0.5 my attributes no more show on product page. no matter what i do. So i reverse to 2.6.14.
now dress size are in letters (M/L, S/M, XL-XXL, XS/S, S-M,) but when i add new product and try put some of these attributes woocommerse add numbers instead of letters. Interesting part is that these new numbers doesnt exist before i add attribute. So after i add attribute on product in attribute page i see that.
2108, 2110, 621, 63, L/XL, M/L, S/M, XL-XXL, XS/S, S-M

Instead of letters add random numbers.
Ny attribute section is also set on Name not numbers.

So please if anyone have clue what to do please will be big help.