fileupload validation not working as expected

Hello,

I have the following validations on a file upload. When I upload a wrong extension for testing, it is giving me a completely different validation message than what I have in my code and I'm not sure where it's getting it from. Also, it looks like each time I upload a new file, the earlier validation message does not get replaced with the new one and I have no point of reference to see where this is happening, if anyone knows how to fix these two issues I'd really appreciate it.

Here is the code. For reference, the constant being used (cons!GF_FILE_EXTENSIONS_UTILITY_PACKAGE_ARTIFACTS) has an array of all valid extensions (pdf, jpg, png, etc.)