A simple part drawing:
Edit the model
See what happened there?
The section line is not constrained to the circle, it accidentally picked up on the mid point of the edge.
Yes the section should, if possible, be controlled by the hole as a matter of good practice but that isn't always possible or desirable.
The point is that if the section is not controlled by the hole - it might be controlled by another hole or a any other geometry that now doesn't line up with the hole after the edit.
The diameter dimension should no longer work as a diameter.
It should detach and go brown,
or the diameter symbol should at least drop off but it should be flagged better than that, (a newly applied dimension appears as just 19.08 in this case)
or it should still display the 20 diameter (but there should be a warning of some sort).
...or something else.
BUT showing Ø19.08 is absolutely wrong and should never happen because it is not a diameter.
Yes I had some weird under size holes in some parts I had made!
File this under "traps for the unwary".