B1/B2 visa app based on via interview waiver

[jhawk]

Hi All,
Long time lurker, first time poster. Thanks for all you do on this amazing website!

My parents had US visas (B1/B2) from before, which are due to expire in October. Due to their currect visa, they are eligible for interview waiver (passport drop off service). The application has already been submitted based on the visa interview waiver program. I just got an application update yesterday saying that they are required to come in for an interview for their visa application. The case reason says 'dropbox related issues'. Anyone knows what this is all about or has experienced anything similar?

Thanks in Advance..

[immihelp]

It could be anything and it is hard for anyone to predict what it could be.

The best thing to do would be to follow their instructions and visit them in person.