unexpected behaviour using parallel execution

Hi guys,

Not sure if it's a bug or by nature of design, but I noticed that after updating some of my outdated loop operators my whole workflow started to fail.

In specific none of my python scripts were running anymore, except if I included a breakpoint in the loop operator. When disabling the parallel execution option all worked again as before. So basically it looks like the process is not waiting for a return of the python operator and just skips it in parallel mode. Is this expected behaviour?

Took me some time and pulled hairs before I figured it out so hopefully other people can learn from this experience :-)