Creating content -greek chars in title- leads to crash or empty slug

[e-me]

~ slugify() | h5p/class-h5p-php-library/h5p.classes.php

[icc]

Thank you for reporting.
Could you include a couple of example strings and what you'd expect the outcome to be?
I'm worried this may be related to charset as well. Using simply a β as the content title seems to work just fine.

[e-me]

...for example a content (library: True-False) entitled 'Ένας Ελληνικός Τίτλος!' cannot be created. There is an infinite loop instead. Is there something concerning the charset that I can check?