I had my visa interview yesterday and my application is kept on hold because I went with a DS-160 form and applied for a B-1 visa, but the interviewer and their manager asked me to visit US consulate again with DS-2019 form for a J-1 visa for my purpose of visit.
My purpose is to visit as an observer and observe my professor's laboratory work to gain knowledge and experience, also in the meantime I'll be getting opportunity to attend seminars related to their work. I'm not getting paid, neither I'm paying anything for this trip. Also the institute I'm visiting is asking me to get a B-1 visa because it is only favouring their policy.
How can I proceed?