I got problems with my iPad Pro on iOS 12.1.4, shown in the video here.
I zoom into a screenshot image placed into a note (note.app). I zoom into it and do my markup (writing on it with apple pencil 1st gen).
Then, when I try to do the same again, I cannot zoom into the image anymore.
So that means: I can edit it once. But I am unable to add anything afterwards, which is annoying.