I mean this as respectfully as possible, but I was asking for more effort on your part than just copy/pasting the large complicated example from the repo. I.e. a minimal example. There are hundreds of thousands of users and only a handful of maintainers/consistent answers. The only way this works if if users put in some effort to ask good, detailed, focused questions.
All that said I just realized what the issue here is. The “press up” event is a touch gesture, only relevant on touch displays. It has nothing to do with mouse events.
If you want to implement drag operations with a mouse then the relevant events are PanStart, Pan, and PanEnd