Hello,
Yes as Graham says you need to remove the chrome plating as this material is too hard for the grippers to cling on to. Use your abrasive of choice to rub down to the copper underneath. Make sure you take enough (length) off, to be safe you should be able to see a little of the de-chromed pipe poking out of the end of the SF fitting once it is fully inserted. Looks a bit rubbish, but then so does SF in general so you've not lost anything!
Failure to remove the chrome plating will lead to the coupling popping off at some point in the future.