Same issues. So far this has been on a staging site, but every other site is also having problems. SiteGround says it’s not them – and nothing that suggests that there is an issue with the site. The server itself is (and has been) running optimally.
Bottom line for me is it is not working. Continually am getting 504 – Gateway Timeouts.
So far nothing is working with this, but I have to move on with my day.
If you have other ideas, I am open to try them.