MySQL replication slave of slave not receiving updates

I have 4 servers: A, B, C and D.

A and B are in a master-master setup.

C is a slave to B and D is a slave to C.

Changes on A or B get to all nodes other than D. I need them to get to D

Changes on C get to D but obviously they don't go to A or B which is fine.

After some reading I found that I needed the log-slave-updates option set on C, this way C would log the changes replicated to it and then D could read those and make the same updates.

I have set the option to on and D is waiting for it's master to send events but changes from A or B are still not getting to D.