Not only a slat problem but for some reason when the slats jammed the thrust went into thrust lock at only 63%, hence the comment about being unsure whether they could maintain their altitude. Also, there were conflicting ECAM messages. Apparently the ECAM was also directing them into a flaps jam situation.
Kudos to the crew. They sorted out the conflicting ECAM, regained manual thrust, actioned the appropriate checklist, and hand flew the approach. Well done!