Basically you can only view content from instances your home instance (in this case Beehaw) federates with.
Unfortunately, a few weeks ago, Beehaw had to defederate from Lemmy.world and Shitjustworks due to a lack of moderation tools.
This means you will not be able to view any Lemmy.world content with your Beehaw account until Beehaw refederates.
You may still see old content from Lemmy.world from before the defederation, but no new content will show up.
My personal recommendation if you want to see Lemmy.world content would be to use the Lift-off app for Lemmy; which can combine multiple accounts' feeds into a single feed. Then you can use a Lemmy.world account to view their content and your Beehaw account to view their content at the same time.
I hope this helps.