OB Mode is very sensitive to errors. If there is an error, then the website is not being pushed out. If you want to use it, you will need to make sure there are no errors at all in your PHP Error Logs, by any other plugin.
Without it, it should also work, but it would only work in the content itself of the website, not widgets, headers, footers, etc.
You might need to ask a developer to help you with your install. The most I could do is to propose those two modes, but in fact, I would prefer not to propose any mode and that everyone has a simple install with no warnings/errors, that’s so much simpler ?? The reality is more complicated unfortunately.