Application.Properties does not work for a minority of users

One of my apps gets ERA reports for "Unhandled Exception" and "Invalid Value" in lines of code related to properties.

In this specific case:

1) I get "Unhandled Exception" in cases like:

var a = Application.Properties.getValue("property1");

The documentation says that getValue() can throw UnexpectedTypeException and InvalidKeyException, which both are not the case because I always use Strings as keys and the key does always exist because defined in the properties.xml file.

2) I get "Invalid Value" in cases like:

var a = Application.Properties.getValue("property1");
if(a == 1) {
    // do stuff
}

Differently from before, it looks like the getValue() function retrieves something, because no exception is thrown, but the type is different from what supposed to be.

This is really strange because these issues happen to a very small portion of the users, and in fact I haven't been able to replicate this problem on both of my devices with daily usage of my app.

Thank you very much!