Nice post, I enjoyed the storytelling. Glad it's all sorted now 😁
Btw, regarding this point:
All in all, this has been a fairly frustrating experience and I can’t imagine anyone who’s not doing IT Infrastructure as their day job being able to solve this. As helpful as the other lemmy admins were, they were relying a lot on me knowing my shit around Linux, networking, docker and postgresql at the same time. I had to do extended DB analysis, fork repositories, compile docker containers from scratch and deploy them ad-hoc etc. Someone who just wants to host a lemmy server would give up way earlier than this.
I think you're totally right, but at the same time, I think the collaborative troubleshooting that happened on Matrix (and has happened many times in the past for other issues) is pretty healthy, and not something that is always possible for other open source software.