Hi @swinter1
UiPath is adding the @ symbol before String1 because it is interpreting it as a verbatim string literal. A verbatim string literal starts with the @ symbol and it allows you to include special characters, such as new lines or tabs, in a string without having to escape them.
To avoid this, you can use:
String1 = String1.TrimStart("@"c)
Hope this helps,
Best Regards.