hey everyone,
as I've mentioned above we have a problem regarding managing sprints. We have a backlog with issues belonging to multiple projects and up until a couple of weeks ago all of our project leads, project administrators and some other roles (i.e. project member intern) were able to manage all the sprints on the board (create, start, edit, complete).
All of a sudden all users that aren't jira-admins (i.e. site- or orga-admin) can only manage some of the sprints on the board. No changes have been made to the permission scheme, board or filter query.
I've double checked if there were any issues in those non managable sprints that originated from a project they don't have the manage sprint or schedule issue permission for (both manually and using the permission helper). For all those issues all of the users have multiple roles that give them explicit permission to manage sprints (and schedule issues) - and still they're suddenly not able to. And the same roles work in those few sprints that they are still able to manage (i.e. in the sprint at the top there are issues from three different projects, for all of them the user who made the screenshot has mutliple roles - both user and group roles - giving him permissions to manage sprints - still doesn't work):

The board filter is very complex since the backlog consists of all the issues (unless they're a "ziel") assigned to one of the teams in the query (custom field):
team in ("team one", "team two", " [...] "last team") AND issuetype != ziel ORDER BY Rank ASC
I know that it's most likely a problem with the filter (maybe some issues slipped on the board originating from projects that somehow don't have one of the above mentioned roles assigned to it) but since our backlog consists of 1000+ issues and has been working fine for almost 1,5 years, I'm still wondering if there could be some other problem behind all of this?
Thanks in advance!