In the vid snap to grid is on, and if it didn’t work after you turned it off is because there is a feature in app which I never liked it but hate! And the feature is that the app keeps the original point in mind when you first dropped the object on! And it really bothers! The problem would be resolved by zooming in or out but not when you do not lock the grid size also😁 which is not the case for you! I mean it seems that you locked the grid size for 0.5 mm
As I said above, the problem would be resolved by zooming in but not when you lock the grid size and snap to grid is on, which is not the case for you! I mean it seems that you locked the grid size for 0.5 mm and snap to grid is on, once you unlock it and turn off snap to grid, by zooming in, you can overcome this strange bothersome behavior, which is intrinsic for the app.
But I prefer to illustrate about that strange behavior simply. See the vids below; first pay attention that both snap to grid and lock the grid size are off. I drew a line from A to B then tried to extend to C but the app doesn’t allow, and the right extremity sticks to its original location but once I zoomed in, I was able to put the end on C.
Not true I think. Even if you keep zooming and zooming the grid will keep dividing and being smaller and you’ll see that you never get to snap to the point like when you are doing concentric constrains for example