Hi Sven,
The account’s sub-pages are loaded based on rewrite rules. When these rules aren’t present, those pages will return a 404 message.
Now, plugins can add their own rules, and tell WordPress to flush (aka rebuild) them. When they’re flushed too early or added too late, things do go wrong.
With that said, The SEO Framework adheres to all these rules, and so does WooCommerce: Add the rules on init
, flush on shutdown
. Unfortunately, many other plugins don’t, and this causes issues that may steer you in the wrong direction.
So, there’s probably another plugin that adds custom rewrite rules and flushes the system too early. Why that happens whenever you save the SEO settings, is still a mystery to me. It could be that one plugin’s continuously flushing the rules in the admin area.
Luckily, you can trigger this issue manually (save the SEO settings…), so it’s just a matter of disabling plugins one-by-one until the issue’s gone. With that, you’ll know which plugin’s conflicting, and you may wish to contact the author on that. Of course, themes also have the power to do this, but that’s ill-advised.
Best of luck!