Hi Rex,
Yes, a year ago or two we updated the tab minimum height to match the increased height of the latest Office versions. The other screenshots you saw were from older versions.
The RibbonMeasurements.TabMinHeight is now 30 but can be set back to 23 to mimic before. Please do that before any UI loads. I don't believe there's a change option for the title bar portion though since buttons in general there are taller now.