As always - any unsolvable problems can usually be remedied by dropping an email to the manufacturer. However, if it isn't venting it's usually an easy fix.
Look at the bottom of the ballast area of the cylinder - in particular, the big holes into the ballast tank. Note the two nuts on a threaded rod in the ballast area. One nut controls the venting (aft nut I think), the other controls the gas blow (forward nut). Turn the vent nut a little, then put the cylinder in the tub and try venting it with the transmitter. If it doesn't vent, turn the nut a little more.
Once both the vent and blow are working, put a tiny bit of silicone on the nuts to keep them from turning. Note - don't crank the nuts down tightly against the brass actuator - they need a little room or they'll bind.
NOTE - When the cylinder is in the tub, make sure there isn't a little gas bubbling into the tank from the blow valve, slowly blowing the ballast. If so, turn the blow nut until it isn't pressing against the actuator unless you are commanding a blow with your transmitter.