Ignition 8.0.11
It looks like system.perspective.getSessionInfo() is returning the wrong sessionID for the designer.
Looks like this has always been the case as far as I can tell. I’ve made a ticket to investigate and see if we can align them (or document the difference if there’s a valid reason they are and must remain different). Thanks for the heads up.
It should be noted: if you’re calling your script from somewhere that has component methods available, calling self.session.info.id will give you an ID that matches the one in getSessionInfo().
And if the only think you need that ID for is the session info, self.session.info may give you everything you need, without needing to call .getSessionInfo().