Screen focus moves between clips in expert mode at magnification
I just installed Mac Premiere Elements 15 (have used 11 and 14 previously) on a new computer. I import mp4 video files (1280 x 720)- one in video/audio 1, the other in video/audio 2. I'm using Expert mode. I apply the Transformation-Crop tool to video 2 and crop video 2. I want to edit around the area I just cropped so I magnify it, to say, 150% and move the focus to the crop area (which is relatively small). I make an adjustment (lighting-brightness) in the color to video 2 which I want to apply to maybe one frame so I clip the frame and make the adjustment. When I move (via scroll left key) to the previous frame (which is now a different clip), what's visible on the window shifts outside of where it was originally. This doesn't happen in Quick mode (but I think Quick mode is useless for what I'm doing). It also doesn't happen if I have video 1 (the non-cropped clip) selected/highlighted and then scroll - only if video 2 is selected/highlighted. It worked as expected in Premiere Elements 14 on a different computer. Is this a bug or is something that maybe unique to my computer?
(I tried searching "magnification expert" but didn't find any relevant posts.)