Pikapig
Loving Analog
Try a different M adapter. You need one with a cutout for the infinity lock.
EDIT: Wait -- I can't really tell from your pictures above but it looks like you're using one already. Odd.
Yes im using a voigtlander adapter but locking it can be done but i find it a hazzle. No worries as i doubt i will use this lens till infinity.🙂
Do share some pics k🙂