SLA timers are wrong
This is patently incorrect behavior so I'm surprised I don't see anyone else reporting it.
Set an SLA timer so that tickets w Priority High must be resolved in 1 hour.
Take an old (> 1 hour) ticket whose priority is Low - set it to High.
SLA alert immediately fires.
SLA's must be set from the time the Priority changes, not from the time the ticket was opened!
If no one else sees this perhaps there's something odd with my setup.
We can completely understand your concern here. As such, the SLA policies are defined in a way to consider the "Created Time" of the ticket as the primary parameter. Hence, if the priority is changed or if the group is reassigned, the SLA would be re-calculated from the created time of the ticket.