How to unlink a Roblox account from Xbox series X account

Hi, hope someone can advise me please.

I've got Roblox installed on our Xbox Series X.

I've got a Roblox user account (e.g. RoAcc1) that currently appears to be linked to my Xbox user profile. I want to break this link so that I can instead log into Roblox using a different Roblox user account (e.g. RoAcc2) from the same Xbox user profile.

Currently, when I try to log into Roblox with the second RoAcc2 account, I can't get past a 'Something went wrong. Please try again later' message.

I've read a help article (link below) that explains how to unlink Roblox and Xbox accounts for an Xbox One, but this doesn't appear to relate to my version of roblox on Series X, as there's no apparent option on the Roblox game 'Account' page to 'UNLINK [YOUR GAMERTAG]'

https://en.help.roblox.com/hc/en-us/articles/360000334523-Xbox-One-App-Trouble-logging-into-Roblox-account

I've been chatting with Roblox support on this issue for a few days now, but without much success.

Please can anyone help?

:)