/gamerule doMobSpawning false and other gamerule commands not working in 1.21.11 (Java Edition)

In Minecraft Java Edition 1.21.11, the /gamerule command does not recognize known gamerules like doMobSpawning or doDaylightCycle.

When I try to enter a command such as:

/gamerule doMobSpawning false

It returns an error saying:

"The number of arguments for the command is incorrect."

The same happens with other gamerules like doDaylightCycle.

I tested:

• With no mods installed (clean installation)

• In newly created single-player worlds

• With and without cheats enabled

• I also verified that commands like /time set and /weather clear still work normally.

This behavior appears only with /gamerule, and did not occur in previous versions.

Additional information about the attached files:

• The screenshots were taken in a world that was originally created in an earlier Minecraft version and then updated to Minecraft Java Edition 1.21.11.
  After updating the world, running the /gamerule commands resulted in the same error message.

• The video was recorded in Minecraft Java Edition 1.21.11 using a newly created world.
  In this video, I attempt to run the same /gamerule commands immediately after world creation, and the same error occurs.

This shows that the issue happens both:

• in worlds upgraded from previous versions, and

• in newly created worlds in version 1.21.11.