When setting up events, the option "club members are co-hosts" either doesn't exist or doesn't list all clubs in some cases.
We have isolated the cause, the wrong search function is being used by the Event Setup functionality, though this has not been fixed as yet.
A workaround for this problem is to go into the Administration link on your club's home page, and set the club to be listed in the directory of clubs. Your club will then appear correctly in the co-host section of event setup.
Thank you for your patience and understanding.