Some WSJ articles work and some don't for me. I think the difference may be opinion pieces.
Not sure about WSJ, but in some cases the extension fetches the content from archive today and inserts it into the displayed website tab.
If there is no mirror on archive today, the extension cannot insert it.
I also point out there is "bypass paywalls" and "bypass paywalls clean", kind of similar to the uBlock family with "uBlock origin" being the "good guy" edition