Multicast NLB does not require any specific settings on the ESXi side.
After that connection from internal network to Internal DA interface is lost. I can ping host IP but not cluster IP, Cluster IP works only from same subnet.
Keeping the above in mind and the fact that you already confirmed that it works in general from the same subnet, I'm fairly sure the issue is not on the virtualization side.
Static multicast ARP addressess are added in ARP -table as they should be.
And on which ARP-table where exactly did you set the static ARP entry? On the router that's forwarding traffic into this subnet on behalf of your clients in another subnet as it should be?