Hello Wondering If any one can help?

I want to list Gym Leggings I have been trying to sort this for about 2 weeks. I have current listing which come under apparel but this is my first new listing in this category and Amazon have changed the requirements.

The old way I listed was basic variation - Colours - Example Black/Grey - Size - Small/Medium/Large/Xl

The new requirements are now - Bottoms Size / Colour / Size

From what Amazon have told me from there help pages I choose bottoms size as Alpha and then choose sizes which fit my product like Small/Medium/Large/XL and then Colour and then Size as regular.

I have done this maybe over 30 times error codes each time that I can not get my head round. The only time I managed to succeed with out any errors it created the listing but not as a parent and child but every size and colour as individual listings.

I have been selling on here since 2018 can usually do most tasks without help but this has got me baffled but I know I am missing something I can not put my finger on what.

Thanks