So sorry guys, we made a bunch of changes on the admin side introducing new stuff (PMs, forum stats, LaTeX, etc.) and every few days those plugins turn themselves off and make the posts 'disappear' until they're reset.
It's extremely annoying, I know, but neither our tech team nor the Flarum forum customer support can work out what's causing this. So we've been disabling those new plugins periodically to see if we can isolate the problem, but there's no way to replicate the issue aside from just waiting to see if the site goes blank overnight 🙁 It's been very sporadic (sometimes two days in a row, sometimes it's fine for ten days??) but I'm doing my best to monitor it and reset asap!
We're trying something new at the moment which will hopefully be a long-term fix.
Apologies to everyone, and thank you for putting up with this terrible temporary invisible mode 😢