OpenVidu Web Error: The plain HTTP request was sent to HTTPS port

We have OpenVidu on premises, with valid certificate. When we try accessing ""https://instance.domain.com it’s giving 400 bad request with The plain HTTP request was sent to HTTPS port error.

Any guidance how to fix that?

Thanks in advance.

Quite strange. What is giving you a 400? The nginx proxy or OpenVidu? What OpenVidu edition did you deployed and how did you deployed?