This is what I get:
I assume that means both screens are working correctly.
Edit: oh wait, I do see that Screen1 joins the existing label value to the label’s text but Screen2 does not. So yes, there’s something broken there.
One of the labels has a persistent value across screens and the other does not. Neither one should have a persistent value. It does the same thing on my iPhone 11 in Thunkable Live. I can’t explain this.