In the Nav Bar Properties menu uncheck [ ] Adjust Button Width to Labels.
Hold down the Ctrl key and click on the rectangle for the Home button.
Make any adjustments. The other buttons will change the match the changes you make to the Home button.
One strange thing with the button bar in my screen shot. When I adjusted the width, the text was Left justified. When I changed the justification to Left justified, then the text was Centered again.
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