Hello! As of recently (the last week or so), there has been an extremely annoying bug regarding Google Authenticator’s 2FA for selling and trading items, it might be affecting other actions but I have not personally tested those (hopefully I have reported the issue to the right category).
Basically, upon trying to insert the 2FA code, an “Invalid Code” message shows up, but the code is, in fact, not invalid. You have to wait for the code to refresh so whatever action you’re trying to execute goes through with no flaws. It’s no website breaking bug, just a little annoyance.
I’m not sure if that’s a Roblox bug or a Google Authenticator bug, but I thought I’d leave the report here, just in case. Thank you for your time! 
(The Authenticator app does not allow for screenshots, but I imagine the bug is really simple to imagine.)
Expected behavior
It is expected for the current active code to work without having to wait for it to refresh.