If you have multiple rows of tabs and you select a tab that is not on the bottom row, the entire row of the tab you clicked is moved to the bottom row.
This is confusing at times since the tabs keep moving position. Can you add an option to keep the tabs rows locked, so tabs can still be moved, but this is the only way they can move position.
You can change the style to “Button” style if you don’t want the row move up and down. You can change the settings in the Customize dialog > Tab > Style.
I was forgetting about that option. As you already have a custom tab/button control, then I’m guessing it won’t be too hard to add the other feature I requested