So this problem seems to be consistent.
It seems that almost every time without fail, after having uploaded a video, when I go back to editing, the timestamps for pins become displaced.
I'm talking about the "orange" pins.
I've noticed however, that if I delete the first pin, the next one will be at the correct place/time again.
So it seems that the pin timestamps are moved forward by however long the previous pin was.
This might not be correct but I think that is what is happening.
Please let me know if this is something you would be able to fix.
It can be frustrating having to re-edit every pin if you notice a small mistake after an initial upload.