Signature Cuffs are now v2.4.3 , which fixes a positioning bug in v2.4.2. In v2.4.2, when you reposition the cuffs, especially in small increments, or in a particular direction, the new position might not be saved. New rezzes might thus revert back to the previous positions.
v2.4.3 fixes that, and will now tell you when it saves the new position, so you know.
If you have v2.4.2, you can choose not to update to v2.4.3 if you don’t plan on repositioning your cuffs much. Or, you are happy to play around with a manual workaround: first slide the cuff a long way up your limb, then rotate to your fancy. Finally, slide the cuff back to the desired position along the limb. Don’t do any rotation after that. You can detach and rez again to see whether it was saved.