Hello, any progress on this?

Sorting For Odoo v18:

The sequence value from older versions is now hidden, so older posts are confusing since they feature a sequence value.

In newer versions to sort product variants do this:
1) Go Sales > Settings > Product Attributes.
2) Select the Attribute
3) Drag the 6 dots (row) up/down and save.
4) [Optional] If there's pagination (1/40 of 150 eg).
5) Click the 1/40 and add a 0 behind => 1/400 of 150
6) This will open up all the variants and let you drag/drop all 150 of them.

Note:
The row order is how the selection of the attribute will be sorted (sales, website etc).

Finally found a solution for this, by importing with the required sequence, any value with a 0 in the sequence will be sorted on the website alphabetically, but if you give the sequence a value it will be sorted in the sequence you indicated, click here for an example import sheet

won't change the variants in the product and on the website

Go to edit mode on the product template, navigate to the product variant tab, and for the attribute you need to correct the values ordering for, simply remove them all and re-add them. As long as the same values are selected (even if in a different order than originally), the product variant records will be the same when you save.

Go to Invetory=>configuration=>Attributes

a list of attributes will appear.    

sort attributes dragging the handle at left

your problem is solved!!

please Upvote my answer if it helps.