Networking Referral Not Responding

This has happened twice now as I keep networking for the summer of 21: a banker I've been referred to does not respond.

First one: I was told by his boss in an email that this guy would connect me with junior bankers. Said guy was cc'd in the email, yet hasn't responded to my followups.

Second one: Friend of an alum's friend allegedly agreed to chat with me, but hasn't responded to my outreach email/follow ups.

What should I do in these situations. My school doesn't have many alums in IB at these banks, so those referrals were pretty important for branching out there. I don't want to go and essentially tattle back to the alums about how these people aren't responding, but also feel it is a terrible look if they refer me to somebody, I say "thanks, will let you know how it goes," and then never even chat with the prospective parties. Could my .edu address be sinking me? Any and all advice welcome.