Firstly, please try updating to the latest SDK, since 1.8.3 is outdated and no longer supported.
If this does not help…
I’ve just tried visiting the URL directly, and it looks like it is stuck on ‘Joining Meeting’. Therefore, please can you set ‘debug’ to true, and then see if there are any errors showing?
Could you also post your join() code so we can see how you are joining users into the meeting?