In a brand new installation of Redmine 3.4.2.stable (under Centos7/Passenger/NginX, if that matters; I can give the whole setup, if requested) I added two more "Issue priorities": "Postponed" and "Background" which should be lower than "Low".
This is how I see the page after creation ("Postponed" and "Background" have highest priority):
I can reorder priorities as follows:
... but I see no way to save the change and, unsurprisingly, if I reload the page order returns back to the original one.
Also in "Issues" page, when sorting according to Priority, Redmine shows "Background" at top.
What am I missing?
What should I check?