Not sure about this one.
@jgthms For reference:

When I remove flex-shrink in the devtools, the title no longer overflows, it breaks to the next line, and the title area grows in height to fit the text.
Here's the commit where you added it in.
https://github.com/jgthms/bulma/commit/9094eff30a0efc938fc921911da8426288e2b1b6#diff-a45c8f59ffab6624ecea0fa76db0e970
I am having the same issue with the .level-item class.
I'm closing this. If anyone still has issues with this ask jgthms to reopen it.
Most helpful comment
I am having the same issue with the
.level-itemclass.