I have the same issue. I tried the international slider switch in the application and it let me enter my foreign address. However, when I saved it, I received a red box stating that my current address must be a US address.

What I did was use my US mailing address on the app and put my foreign address on my resume. My application has been like this since January and is still active. My foreign address on my resume did not seem to be a problem when I spoke with UPS at OBAP.