How do I trim a clip and ripple without damaging previous clips?

I have all of my clips overlapping by 1 second, covering 5 different video tracks. (for transitions)

I want to trim a clip, and the time cursor is only intersecting one video track. (so I’m not doing any trimming during the overlaps / transitions!) I press shift + i, which does exactly what I want to do in terms of trimming the clip, but it ends up somehow also trimming the “out time” of the previous clip, and at the same time destroys the video fade out filter of the previous clip. Also, ctrl+z doesn’t undo this change, in fact it deletes the previous video from the timeline entirely. (again, the time cursor only intersects with a single clip!)

How do I trim a clip with shift + i, rippling all following clips, but not touching any previous clip?

I can get basically the edit I want by locking the video track that contains the previous clip, but of course that means all following clips that reside in the locked clip won’t get rippled correctly.

I effectively need a way to just lock a clip, so it doesn’t get damaged somehow by trimming a subsequent clip.

To reproduce this issue, try making a test project with a few tracks and a few overlapping video clips, (overlap by say 1 second, and give all clips 1 second fade in and out) then try trimming one of them with shift + i and see what happens to the previous clip on the timeline.