In Tracte Megilah 13a - it lists the children of בתיה - the daughter of פרעה.
One of the children's names is חבר - father of שוכו.
The Gemara then explains that all of these names of the kids - are all really משה רבינו!
The Gemara then explains why משה was called these names.
When explaining why he was called שוכו - it says "סוכו" with a "ס" - not at "ש"!
Why does the spelling of the name change?