For devs… It appears that values are not being changed back to original values upon going back in history using the history setting.
Using Pro 2.3
example to produce this:
While in header builder, while editing off canvas base font size, I changed it from 16px to 24px.
Then using the history tool, I reverted it back one step in history. The font did in fact go back to 16px as expected.
The number in the field did not change back from 24px to 16px.
Screenshots attached in sequential order


