Markers Remaining/Offsetting after Deleting/Slicing Part of a Clip

Story for recreation: I was using the timeline with only 1 video stream/file. I added multiple markers to the video on the timeline. I was saving the initial "slice" of the video stream by slicing it at the marker and then deleting the later portion [all the rest/right of the timeline] to leave me with only the file that I needed to save. I then undo the deletion of [all the rest/right of the timeline]. After exporting the clip into a video file, I press CTRL + Z to undo the deletion of the sliced clip to the right and then I delete the clip on the left (which I already exported). The markers from the deleted clips still remain on the timeline.

I still find markers remaining from deleted clips left of the timeline. It appears the markers from the delete clip do not disappear but remain on the timeline.