That’s certainly a weird behaviour. And it’s more interesting that there is an extension just to enable reader mode, though kinda understand if it works on every page.

can’t wait for them to start injecting ads into reader mode or to outright reject toggling the mode if some kind of advertising meta tag is present.

I hope it never come to that but as long as Firefox lives, we’ll have forks like Librewolf. So it’s not really a problem.