Please try to comment and post things now, and see if they federate again.
Hopefully you see your activity instantly federated. I have tried making comments both to instances running Lemmy 0.19.1 and 0.18.5 and they all federate like they should.
Hope you have the same experience! 🥳
Seems federation is still not fixed even though it certainly helped to federate some things, while leaving others… :/
On the positive side, the pull request that may fix federation properly in the software was approved by one of the Lemmy devs 2 hours ago so it should be merged with the main code soon:
https://github.com/LemmyNet/lemmy/pull/4330