Steps to Reproduce
Create a Blank Game project in UE5.5.4
Create a new Actor BP add a new Variable of type Text Array.
Save & Compile
Instantiate this BP into the world.
Save & Compile
Add a new entry in the default value of the Text Array. (entry 0, Text1)
Notice that the new entry is propagated to the Instantiated one in the World.
Add a new entry in the default value of the Text Array. (entry 1, Text2)
Notice that this new entry is no properly propagated to the Instantiated one. (new row but empty value and reset arrow displayed)