Had about 5 times on the 734 over the last 7 years ranging from between 1 and 5 to 25 and 30.
The immediate recycle of the flap level always bear no results. Best to discontinue approach,proceed to a hold,have a sip of water for a few minutes then most probably the larger flap will move back to the position commanded by the level which is a smaller settings once the system unfreeze its sensors and components.In case of hardware failure,do the checklist and land a little faster than usual with no drama,unless flap less than 5 with bald tyres could be more interesting.