Mac OS X - Qt Creator - Text editor - distortion of image of lines of code while scrolling and selecting the blocks's content

When I open files of project, I see distortion of view of lines of code. It manifested in two cases at least:
1) When scrolling down and then scrolling up of code. It distorts text.
2) When scroll away from current page and to click on code block - all code on the screen shifts slightly
Qt Creator Text Editor Preferences: Font: Monaco, Size: 20, Zoom: 90%
If zoom is 100% - first issue will disappear, I think.
Screenshots of first case are included.