Crepes sliding off crepe maker base
If the first half of the recipe worked fine, it sounds like your crepe maker might be losing heat. Try giving the crepe maker a minute or two to reheat in the middle of your cooking.

Don't necessarily trust the ready indicator either. An infrared thermometer would help, but you can also drop a few drops of water on the grill. If the water quickly sizzles and evaporates, it should be ready.