We have a fix in the next version for the menus only (the linked post above). The problem you are showing is affecting some non-menu text. This will have to wait until we can do upgrade our main library to the next major version. In the meantime, as a workaround, you can run Shotcut with command line argument --QT_SCALE_FACTOR 1 or 2 if you want 200%. It is the fractional scaling that is sometimes a problem.