Categories layout will not stay in correct order

I have a list of brands that I want to appear in alphabetical order but no matter how many times I put it in the correct order it changes it to some random order.

Every other category I have is ok and if I want to change the order I just use the 'order dots' to drag them into the correct place.

Can you please help?

Sharon

I've just kept on dragging them into the correct order (about 15 times) and now they are staying there. Don't know why they wouldn't before.