Shimano/Wipperman Connex compatability

Hi I attempted to replace a 105 11 sp chain with a Wipperman Connex equivalent. The result was severe clicking on the 5 largest rear cogs. No amount of micro adjusting would solve it so I had to temporarily re fit the old chain and the issue was resolved. Now having bought a new 105 chain I find the Connex quick link pin is too large to fit the 105 chain. Am I missing something here. The Connex link is also 11 speed fir sure.