There's a merged pull request on the void-packages repository

linux5.5: enable ipv6 multicast support
https://github.com/void-linux/void-packages/pull/19459

Description:
We are missing multicast support for ipv6. I'm packaging a couple of necessary tools after this is added in some shape or form. 
I'm not sure how or if we want to backport these changes, so wanted to hear what you have to say.