I'm using PhpStorm and Xdebug for a variety of different projects.
I'm not sure what caused it but recently debugging only works as intended for one of my projects.
For all my other projects debugging doesn't work and whenever I have the option "Force break at first line when a script is outside the project" ticked, debugging starts at the first line of the one project for which debugging actually works. Subsequent breakpoints in the project I want to debug are not reached though.
So obviously there is something wrong with the way projects are identified. But I can't really find how to configure that in PhpStorm.
The reason why my debugger jumped into one specific project was active cronjobs which were running even when I wasn't actively using that project.
I checked for the cronjobs using crontab -l and then edited them using crontab -e, simply commenting them out for now.