The tabs aren't reordering, the rows are. That's normal. All multi-row tabs work like this.
Whichever row contains the tab you just clicked must come to the front in order for you to see it, and so that the tab is connected to (immediately above) its content.
If the row containing the active tab didn't come to the front, you'd have rows of inactive tabs between the selected tab and the window content which would be very confusing and break the "tab" metaphor, which is modeled on the tabbed physical folders that contain groups of files in a file cabinet.