I’m a first-time poster - but a long-time user. Your excellent communications leave me trusting that you actually do read and comment on these notes, so I joined up. Thank you.
I’m a stickler for keeping my individual mockup canvases in the same position. I do this to facilitate toggling between two canvases quickly to see the difference between the two. I toggle by either clicking on the mockup name on the left of the screen, or using Ctrl-PgUp and Ctrl-PgDn to move between adjacent mockups.
Sometimes, for some unknown reason, the canvases which I leave scrolled to the top-left (so pixel 0x0 is in the top left), get themselves shifted over and/or down by 10 px. This is really annoying, as I then click on each mockup, in turn, and scroll it to the top-left position.
After this scrolling-fest, everything is fine. Until sometime later when the shift comes back.
Unfortunately, I haven’t found any rhyme or reason yet as to the causes leading up to it – so I can’t really hazard a guess as to what’s going on.