Hello,
i wanted to filter for issues which are not Bugs and not Tasks. Additionally these issues should not have the component !=WS10. However, tasks and bugs are still shown in backlog if i filter:
My query: issuetype != Task or issuetype != Bug and component != "WS10 Arbeitsvorrat"
I also tried:
issuetype = "Change Request" or issuetype = Story AND component != "WS10 Arbeitsvorrat" or component is EMPTY, but then some stories disappear where component is None.

Maybe the solution is somewhere inbetween my two queries. Thanks for your help!