Please note: WordPress appears to be failing badly at this stage. I’ll be working on a fix this week, and likely will create a new site out of different, less buggy code.
I’ve checked the DB, moved it to a different machine, restored from a known working backup. It appears a recent update of WP managed to completely screw up post handling. I disabled all plugins, ran health checks, etc. I’ve cleaned cookies, browsing history, used different browsers on different machines, with exactly the same outcome.
A shame, as I’ve used WP for about 13 years at this point. Looking for other SW now. More soon.
[Update] I’ve gone all rogue and VM-y. New fresh WP install on a fresh new instance. I found the handy export/import tools. And I used them.
Lets see if this works. Back to installing plugins for protection.