Scheduled publishing failures

Hello All,

We've been struggling for a while with scheduled posts, sometimes they work, sometimes the schedule is missed and it's not published at all. I've done some research on cron and how it works but I can't get it working. It doesn't seem to be the server as other websites seem to work just fine, but then again, it seems rather random as well so not sure.

The website would be, I know it's not wpmudev related but I'd love some suggestions.

Thank you!