Update: Issue resolved. Thanks for the help @ruud@lemmy.world , @jgrim@discuss.online and everyone else.

I am discuss.online user, and from past few days, it is not syncing with lemmy.world.

The posts and comments made on lemmy.world communities show up on discuss.online, but they aren't synced back to lemmy.world server.

One example is this comment by the discuss.online admin: https://discuss.online/comment/1101565 It doesn't show up on: https://lemmy.world/post/2424133

There are many other such examples. The admins at discuss.online have checked at their side and can't find any issue. Can you check if there's something at your end? Or if there's something that discuss.online can do to make it work again?

Thanks.

Edit: Just want to add, discuss.online is not having any problem with federating with any other server. At least those that I have tried.