I am able to reproduce this again in Windows.
Shotcut 3.mlt (4.4 KB)
shotcut-log3.txt (54.6 KB)
Playing the exported MP4
I think I figured out the issue. The VUI box around the text has to be larger than the font size.
Shotcut 3 v2.mlt (4.4 KB)
This mlt works as it should, or at least how I perceive it should work by design. I had to increase the box around the text, and it now clearly shows when clicking on another track or output.
For a font size of 250, the background size height has to be 413 or larger.
