So this one is pretty specific, when you make a template title clip with %s for the text, and a "scrolling" animation by moving the start and end points, when you add the template title and fill out the text with multiple lines of text, the clip itself will become fully transparent (no text) before the end of the scroll. The title clip 'empties' when the first line goes out of the screen, aka the same line as the %s. If you add multiple empty lines after the %s when you make the template, the clip will empty after that number of lines.
I'm not sure it's clear at all i'm sorry, hopefully trying it will show the issue.


STEPS TO REPRODUCE
1. open title clip window, write %s in the middle centering the text
2. animation time: move the start just above the %s and the end quite bit under, at least a frame height lower
3. save the clip as a .kdenlivetitle
4. Project -> add template title, fill out the text bow with multiple lines of text
5. Play clip to see the result

OBSERVED RESULT
clip empties before the 5s are up, with text still on the screen

EXPECTED RESULT
you can compare by going back to your first tile clip and changing the %s for multiple lines of text, it will scroll until the end of the 5s

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION