Long standing open issue in Asterisk
https://issues.asterisk.org/jira/browse/ASTERISK-17049
Editing a queue ring strategy to linear or one of the round robins, or adding/changing static agent ring order, requires Asterisk to be restarted in order for the changes to take effect. Recommend updating the ring strategy tool tip to add,
> "Some ring strategies (linear, round robin) require Asterisk to be restarted for changes to take effect."