I don't believe it is inappropriate or potential discriminations to conduct some interviews in person and some via virtual platforms. I would recommend that the questions and format be consistent and the fact that it was in person or virtual should not play into the decision as to the candidates qualifications.
You can use this OFCCP audit checklist to ensure you're doing what is required to maintain OFCCP's regulations including VEVRAA, Section 503, and EO 11246. Or request a demo to streamline your compliance and recruiting efforts.