I have retired from my Institute and my official email is disabled and for verification only institute email is needed. How to get verification without official email?
I have exactly the same problem and do not get any response from ResearchGate to my e-mails nor are they available on phone (I am in Germany where the non-US part is located).
Did you receive a re-verification request? I have, but re-verification is not possible without institutional email and my verification will soon expire. Has your verification expired and, if so, what happened then?