I have a minecraft server (with more mods) and i want to keep my iron farm loaded, but when no-one is in the zone the chunk loader just doesn´t work, the floating thing its going up and down and there is not redstone touching it

Similar problem here, I added the mod in forge 1.16.5.
When nobody is near it or online, it does not work.

This should be resolved in the next release.

Version 2.9.0.87 has now been released which should resolve this issue.