Hello,
To double check that the plugin installation hadn’t become corrupted in someway, I deactivated IgniteUp and deleted all the files. I then reinstalled again. However, I’m still having the same problem.
I deactivated all plugins except YoastSEO and IgniteUp and Yoast stopped working. As soon as I deactivated IgniteUp (when no other plugins were activated), Yoast started working again. I don’t think it’s a conflict with anything else, as the problem occurs when Yoast and IgniteUp, or Visual Composer and IgniteUp are activated without any other plugins.
Hope you get it figured out because the front-end looks great. A quick way to set up 503 is a must for me, so at the moment, I’ve switched to a different maintenance mode plugin which had this included.