2013 MINI Cooper S Clubman - Anyone else have this CEL?

Engine warning light lit up (yellow) - full engine power no longer available. Repair shop downloaded computer codes, which indicated camshaft exhaust stuck, so they checked oil and vanos filter for debris, but found nothing. Warning light did not come on again after computer was reset and test drive (4 miles). I subsequently drove car about 30 miles, but warning light did not come on. Anyone had this same engine light come on?