When I leave my M400 in the pool it is on the bottom and when I come out the next morning it's floating. I get in and turn it several ways, sideways and upside down, til no more bubbles come out and it sinks to the bottom. Next day it's floating again. Anyone had the same experience and has discovered where the air is coming from? This doesn't present any problem, if I turn it on while it's floating it sinks and goes right to work.
PS: Love my Dolphin