From Discord:

I'm running my own Hubs Cloud on AWS and added discord bot to my discord server. Then, I created a room by bot. when I click to enter a room the message "You'll need to sign in to Discord to access this room" comes out
hong Robert I think I figured out where this bug is coming from as I ran into it myself. If you are signed into hubs on an account that does not match the email of your discord account, you get an infinite loop of the screenshots hong shared.

So I guess it is intended that you cannot log in this way (although it might be better to throw an exception). I see the logs on my aws instance make sense as well - you get a 'REFUSED JOIN' entry

Hmm, what do you mean by infinite loop? I think that is expected behavior.

It loops between sign into discord (https://discordapp.com/channels/498741086295031808/537752059991031818/754378149122277497) and bot authorisation (https://discordapp.com/channels/498741086295031808/537752059991031818/754378250666639421)