Google apps script issue - script.google.com refused to connect - google glitch

One of our servers which had a google apps script embedded in a php page started showing "script.google.com refused to connect" - the issue was noticed last afternoon. We checked that no changes had been made to the script, we did have

.setXFrameOptionsMode(HtmlService.XFrameOptionsMode.ALLOWALL);

as mentioned in

https://stackoverflow.com/questions/57138352/apps-script-refused-to-connect

The only other change was to install and set up fail2ban on the server, that was unlikely to be the cause. 

"If no changes have been made to the script, then perhaps it is a transient google problem, and might be resolved in a few hours.

If not, we would need to check if google apps scripts have any recent policy changes."

It might have been a google glitch, since last night the issue was resolved by itself. Looked like the outage was for around 8-10 hours.