I believe this only happens since a few weeks or months. When I type a value for the margin for example and press the tab key first the blue dot will be selected. So now I need to press the key 3 times to go to the next input field rather than 2 times.
For me personally even the unit does not need to be selected via the tab key because we can just type the value but I think since this is a selection field it probably needs to be this way.
So this is a minor inconvenience but it bothers me every time hence this feedback.