Opera adding X-FRAME-OPTIONS: DENY?

[b1ackhawk]

b1ackhawk last edited by b1ackhawk

I'm trying access Azure webssh and the iframe is getting blocked by opera with message:
nodename.scm.azurewebsites.net is blocked
nodename.scm.azurewebsites.net refused to connect.

ERR_BLOCKED_BY_RESPONSE

It works fine on Chrome, Brave, Edge and Firefox. I notice that in Opera I see X-FRAME-OPTIONS: DENY is set in the response headers, which does not exist in the other browsers (See screenshots).

Opera GX:

Brave:

What gives?