White Triangles in Upper Corners of clip have disappeared

I've also found this bug.  It is frustrating, because I like to look at my timeline and quickly know if the full sequence is there. In other words, I would like to know if I have accidentally chopped the end of the sequence.  Anyway, I found that if I create a new sequence from scratch, copy the contents of the old one and paste into the new one, and paste the new sequence into the parent timeline, then both triangles are there.

I seem to be able to recreate the bug.  Suppose I have a child sequence and I nest it iin a parent sequence.   Now suppose I edit the child sequence and the child sequence becomes shorter in length.   In the parent sequence, you will now see diagonal bars were the child sequence has effectively vanished.   You can shorten the child sequence in the parent sequence, and get rid of those bars, and in principle the right hand corner triangle should reappear, but it doesn't, and it never will.  Even if you delete the child sequence and paste it in again, the right triangle is gone for good.   At this point, you have to create a new sequence from scratch, and paste the new one.

Yep, looks like a bug. I was able to reproduce it on my system. What's interesting is that if I duplicate the media file in the OS and then import the duplicated/renamed file into Premiere it shows the correct right-handle - so same exact file just different name. If I then move the duplicated file to a different directory and change its name back to the original file and import then Premiere again shows the correct right-handle. So it appears to be a bug where Premiere has some internal metadata associated with a specific file (path+filename).