Yes, there is a tiny amount of play. Just force it back and forth between the stops and it should finish the cycle. I have had the same problem before, I twisted it fairly hard, but want to be careful about putting that advise out there!
The cause was the pins on the lens side were sticking for the first part of their rotation. Lens dis-assembly, cleaning and light lubrication was required.
Thank you for the link, will keep working on it.
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