My Power Armor is damaged. The left leg shows red.

But, when I dock it with one of those yellow power armor stations --- nothing happens.

I am not given any menus to fix the armor and I would think that was what a station was for.

I've tried walking up to an Armor station too but it always says I don't have any armor that needs repair.

How can I fix my Power Armor?

you have to enter the menu in the yellow station, then you should be able to repair the damaged parts

Thats a bug then because you should be able to "craft" on the stand with your power armor near.