Last night during ZRL I made it to level 49 and got the Giro helmet. I went in my garage to check it out after the race and noticed my ZC hat was gone!!!
I exited and reloaded Zwift and it reappeared. I believe this is a bug that removes the hat everytime a new item is added to the head gear section of the garage, but after you reload the game it all gets reshuffled and comes back. @shooj FYI.