Hello, I bought this lens on ebay and I have a proble. This lens has a Fujia X M variant mount. I tried to screw it on this adapter . It screw but don't lock. I think it's because it doesn't tun far away. Possibly because of this metal leg. On this other FX Porst lens The leg is a little bit different it seems to screw a little more and it lock. Do you have any suggestions to help me to lock my lens on my adapter?

Tank you