The inconsistency happens if either the setter is implemented to do something in addition to calling someProperty().set(..) or the getter returns a value != property.get()

The issue was detected in a comment to PR 683 (https://github.com/openjdk/jfx/pull/683#discussion_r758422823) for VirtualFlow.cellCountProperty and positionProperty, the former fixed along with the PR.

There are others, though, which we might collect here (or somewhere else?) and fix in separate (?) issues, probably dependent on how frequent it occurs. Starting a list:

DatePicker converterProperty (here the getter is the problem)