This issue is not caused by just being on Jira 8. It is related to the board page you are looking at as well.
In Jira 8.5.0 and scriptrunner 6.4.0-P5 if you define a behaviour on a field (field level behaviour script), the inline edit should be disabled for that field while on the issue details view.
For a Sprint board:
If you first navigate to the Active Sprints view and perform a hard refresh the validators endpoint is never called and behaviours are never applied to the issue details view. If you, however, load the Backlog view and hard refresh, the validators endpoint is called and behaviours are applied and the inline edit is disabled.
For KANBAN boards:
It seems that for default KANBAN boards that do not have 2 board views. i.e. only one place where you can view issue cards and open the details view. The behaviours validator endpoint is never called and behaviours are not applied at all. Therefore on KANBAN boards, the inline edit is never disabled.
The videos above show how to reproduce. Essentially it does not matter what behaviour code you have on the field as any code on a field disables inline edit. The problem with the fields not getting the inline edit disabled is specific to the board page you are viewing. It appears as though behaviours are expecting something to be on the page to trigger them to load but certain board views are missing this element and so they never get triggered.
- Add a text field to a SCRUM and KANBAN project
- Add a behaviour and add each field as a field inside that behaviour.
- Put 1 line of code in the field level script like "def test = 1234"
- Map the KANBAN and SCRUM project to that behaviour for all issue types
- Go to the standard issue view page and the inline edit will be disabled correctly in both SCRUM and KANBAN
- View the KANBAN board, add the 2 fields to the fields shown in the issue details view, refresh the entire page and you will be able to edit the fields inline. This should not be possible
- View the Active Sprints page for the SCRUM project, again add those custom fields to the Issue Details view. Hard refresh the page and the inline edit will not be disabled. Then go to the Backlog view, hard refresh the page and the behaviours will kick in and disable the inline edit correctly.
- If you watch the network tab you will see no calls to the validators endpoint for the pages that do not load behaviours and you will see it when the fields get disabled correctly on the SCRUM Backlog view
You should not be able to inline edit a field with a behaviour configured while on the Issue Details view for SCRUM or KANBAN boards in any of the views that show the issuee details pop out screen..