Why default priority changed automatically

[Jason Liu]

I have 2 script runners mapping with 1 project. One for Bug issue type to hide other priorities, only show P1-P4. Another for task, story, epic and subtask issue types to hide other priorities, only show Highest, High, Medium, Low, Lowest. I tried to set the default priority as the original "None", issue type as "None" or "Blank". But when I tried to create an issue, the default first will show none or blank, but when I change the issue type from story to bug or else, the priority will change to P1. Can someone recognize this issue?

[Brant Schroeder]

@Jason Liu 

Each project has a priory scheme associated with it.  In that scheme there is a priority default setting.  I would suggest checking that to see what it is.  You will want to set the default to none on the scheme.  https://confluence.atlassian.com/adminjiraserver/associating-priorities-with-projects-939514001.html