Any suggestions on a low maintenance ball trap type cage that can be worn for several months with minimal maintenance?
Something in good quality stainless with an open design like the mature metal jailbird. Sized properly (not too small) it cleans easily in the shower or bath, and you can powder and/or lubricate if you wish without removing it. I think mine was off for less than 6 hours total last year. Good luck.
I would contact MM for advice and to see if an adjustment would help. That said, my first MM cage was a queens keep, and I had a similar issue. The wide band at the base of the cage was trapping moisture. I learned to use a blow dryer after washing followed by powder to keep everything dry and able to move, and the problem went away. After a couple of years I changed to a jailbird and it's much easier to clean and powder.