Mapping custom fields to activity entity from Contact

Hi all,

I want to map some custom fields to custom activity entity from Contact. So, I created one custom relationship (1:N) as we can't add mappings in OOB relationship. Everything is working fine when I am creating an activity from related entity navigation but it is not working if I try to create from "Social Pane". Is there any known issue in D365 On Premise (8.2.2.112) version?

Thanks,

Phani.