I believe that Sketchy really doesn't pay (already had such issue) when it accumulates gold while mining isnt working.
It gathers gold and doesnt pay, and when the server is restarted or whatev it gets rid of all gold accumulated, but pays ONLY the last deposit of all it should pay. So if it has 36k accumulated (for 6x 6k payments) the 30k vanishes and only last 6k is paid.