You can no longer toggle/select multiple stacked Markers. Clicking the multiple stacked Markesr always selects the first Marker, intead of selecting the next Marker in the stack.
Then dragging the Marker also drags all Markers with it, when only the first or selected Marker should get dragged.

repro:
(open project and test scene or)
- create a Timeline
- add 2 Markers on any track
- move one Marker over the other... a small "+" should be added to the Marker.
- select the stacked Marker...
bug1: clicking the stacked Makers always selects the same first Marker.
expected: clicking the stacked Markers should select the next Marker.
bug2: moving the first Marker of the stack moves all Markers with it.
expected: moving the first Marker of the stack should only move the first/selected Marker.

this is a regression.
repro with Timeline 1.4.3
not repro with Timeline 1.4.2