This should probably be invalid because 1) structures can be specified to spawn after world gen and 2) this seems more of a feature request.
This is not a Realms bug, but is a bug with the /place command where the hay bales are not there for the client, but are there for the server. I don’t know the exact issue, but this should be a duplicate.
It seems that at some point between 1.21.90 and 26.40, the generation was changed, producing just monoliths, and no lava lakes.
Both are intentional. Honestly, this bug report is more of a parity request
Invalid, you can change the UI screen in the F3 settings, which can be accessed through pressing F3 and F6.