The reason for this is, that Google is sending an "X-Frame-Options: SAMEORIGIN" response header. This option prevents the browser from displaying iFrames that are not hosted on the same domain as the parent page.
Your iframe behavior is normal and It has nothing to do with SAS Configuration.
To solve this you should do some configuration in your SAS Viya's Apache Web Server,
But I strongly recommend to not do it because this option is set by default to prevent clickjacking for your Apache Web Server, for more information, you can refer these links:
https://geekflare.com/secure-apache-from-clickjacking-with-x-frame-options/https://stackoverflow.com/questions/27358966/how-to-set-x-frame-options-on-iframe
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