I think I'm missing something fundamental

@BryanB, I also run a mocknet browser built by myself on 64-bit linux (Arch) and I have no problems running a right console. In fact, I cannot find the other console that you are talking about (browser console). Maybe you faced the same problem I’ve also faced recently - I didn’t know that beaker:start and safe-auth://home/#/login pages are also HTML pages that you can run console on - maybe it’s the “browser console” that you write about? I attach two screenshots - of console fired on my localhost:// test page and second - the browser’s authenticator page. Maybe this rings any bell?