No should only be one solution
Here’s one I made up that has two solutions (probably a lot more):
x spok wqyyb uqllpmn.
I love happy maggots.
I herd bunny muppets.
And before you call it a dumb cryptogram, let me hasten to say that I’m not proud of my creation.
The point is that it’s not impossible for a cryptogram to have more than one solution, especially a short one.