BHX500 horizontal drilling

BHX500. We are currently having a problem with horizontal drilling in the Y-axis, bottom table only. We can drill horizontally but once horizontal drilling is finished we get an error saying the drill head is not in the start position. If we wait around 30 seconds the error removes itself ( I am thinking the drill head creeps back to its register during this time) and vertical drilling/routing will then commence. Has anyone else had this problem?