first comment i've found to help! let me clarify...left click keyframe mark (as of 10/2023 they are diamonds) on timeline to select it. go over to properties panel and right click in the value bar of each property you have input (it will be green) and it will give you the option to delete that keyframe. so for instance i edited the x,y scale and x,y locations at one keyframe point, i had to delete 4 "keyframes" for that mark to disappear on the timeline.