I have the same windlass
and it's new. Recently had same problem. The electric motor
in your case is making noise
so it's ok in dropping mode. I found, in my case, that sufficient weight needed to applied to anchor chain for the down function not to skip (the clanking sound you hear). Answer in that case is to lower enough chain by hand to apply adequate weight on windlass, then it works fine. Don't know if you can change settings on windlass to avoid this and it isn't all that convenient but that's what I do.