If by "warnings" you mean the orange underlines of that section of your code, neither. It is a feature not of App Designer but of Code Analyzer, who's warning you that you may have meant to reference the object property but instead are creating / referencing a local variable by that name (which may or may not exist.) It's trying to alert you to a pattern that looks like a potential bug in your code.
See the "Adjust Code Analyzer Message Indicators and Messages" section on the documentation page linked above for different ways to suppress that message if you understand its purpose and know you can safely ignore it.
