Hi, Just joined to say that i received this chair today and it has the same issue.(UK)
I've raised a ticket via the link above to request as replacement base/piston as others have. fingers crossed this is sorted fairly quickly.
Excitement for my new chair to arrive quickly turned to disappointment once i assembled and sat on it only to find it's maximum height is still quite low due to the issue with the piston poking through the base too much.