Does on_member_join not fire for Twitch Sub Enabled Servers?

[EggsAndSham]

Hi folks, I've hit a wall trying to debug why my on_member_join listener isn't firing for specific users.

I have the proper intents enabled and in my test server it works for every user that joins, every time they join.
When running the same code for a bot in a "real" server, it works much less often. The first thing I do in the function itself is log some information, and that line doesn't get hit- so I think the function is never being called for this subset of users at all.

So far the only clue I've found is that it seems to stop working when the user is subscribed to the Twitch channel that is connected to the Discord server in question and has their Twitch account linked to their Discord account. I tested this by:

• First having a user join the server with no subscription or account linkage. The listener fired, wrote its log message, and performed the rest of its functionality
  • I tested having the user leave and re-join the server without changing anything, too, which still worked
• Next having that same user leave the server, subscribe on Twitch, link their Discord account to their Twitch account, and then re-join the server. The listener did not fire and nothing was logged (but they DID still get the default Discord random welcome message)

I haven't dug at all into how the Twitch integration works (Maybe they're doing some sort of pseudo-adding-users-to-servers thing when someone links their accounts? Maybe it's when the subscription would grant them some preexisting roles in the server they'd be joining?), but I was curious to see if anyone else had run into this before or had any advice.

Thank you!