Sprint field not populating until you access the board's backlog

Issue Summary

While creating/editing issues, when you try to enter a value in the Sprint field, it will not show you the suggestions/all sprints values. If you already viewed a board's backlog, it will show you only the sprints of this board, despite having access to edit sprints from other boards.

Steps to Reproduce

1. Install Jira 8.11.0 (problem is not reproduced in 8.10.1)
2. Create some projects, boards, and sprints
3. With another username (that didn't access the boards but have access), press the Create button to create an issue and try to use the sprint field
4. You won't see any sprints

Expected Results

1. By clicking in the Sprint field it should show the available sprints to select it to add to the issue

Actual Results

1. You won't be able to enter a sprint in the field as it will show you 'No Matches', or you will be able to see only the sprints from boards there you previously accessed (backlog): 

Workaround

1. Access the Board's Backlog page (from all boards that you need to see sprints in the sprint field)
2. Create an issue >> you'll see the sprints present in the field.