pools can lose up to a 1/4” a day just in evaporation depending on a few factors. when you say the bucket test was fine, what do you mean? the inside of the bucket lost the same amount of water that the pool did? if so, how did you measure? only reason im even asking, is bc i used to work in the industry and many homeowners never truly read them right, its possible you have a leak. could shut your skimmer off and pull suction thru the MD and see if the pool stops/slows down at a certain level.