i have a big gun evo r slip on bought from Motosport. i have a stock header pipe on. my muffler connector ring keeps coming off and leaving my exhaust loose from the header pipe. I have replaced the muffler connector 6x's, my clamp is tightened. I dont what what keep causing it to come loose

 

pictures may help

 

Does it take springs to help hold the two together? Might be time for fresh if so.