Hatch get anormally overcrowed

I hesitate to respond to an expert players bug report, but you have 6 critters and eggs in that room, the critters and eggs require 12 tiles of space each, meaning the space required is 72 tiles for the ranch. This  explains why you are getting the “Cramped” message with a ranch only 48 tiles in size.

I test your save file, once I removed the eggs, the Stone Hatches we no longer cramped.

As an aside, this does mean that the Critter Drop-Off does not help with the Cramped debuff/status, since it only looks at critters, not critter and eggs.