I didn't have an issue with disarming traps yesterday. Astarion passed his Perception checks, I right-clicked on the trap to bring up the menu, and Disarm was an available option (not greyed out) and he disarmed everything.
It's possible that you were walking alongside someone else in your party that they passed the Perception check, but your Rogue failed it. As long as the character who passes the Perception check has the ability to disarm traps and you have a trap disarming kit it should work.
