Lines Lose Original Angle When Switching Between Charts

Say in Chart 1 I have a trend line drawn from a period somewhat far back (where the start of the line is out to the left of the screen, further back in time). Then I switch to Chart 2. Then I switch back to Chart 1. Now the line in Chart 1 is askew - it is at a different angle than when I first created it. I then have to zoom out until the line’s start is displayed on my screen in order to make it resume its original angle. I then may fail to see trend lines, as the angles of the lines are all off.

I am in fullscreen