It looks like the Ethic Legion forks are meant for ICS, but you can use them with SCS if you cut the top of the forks off and install a starnut. I presume you've done that and you're using SCS correctly. If you haven't, then your SCS will never work correctly. So if you have set it up correctly and it's coming loose, you can add a little bit of heavy machine grease to the compression bolt to cause it to move more slowly under vibrations. Also, make sure that you tighten your bolts a little at a time, but favor the bars or the fork a tad if one is slipping in relation to the SCS. Also, make sure your fork and bars are clean to help the SCS clamp grip them tightly.