Error 8015190A after trying to view Purchase History

I have an Xbox Series X and a Xbox 360 Elite (ver1).

I bought Final Fight Double Impact earlier today as it showed that it was "+Xbox One" compatible. After this, I successfully downloaded it on 360 but was unable to do so on my Series X as I would normally. There was no entry for the title under "Games to Install" in my Full Library. I started gathering screenshots ready for a support ticket. I went into my xbox 360 settings and selected profile and "Purchase History" where it prompted me to an automatic download of Internet Explorer on the 360 UI. Once this downloaded my problems really began.

From that moment on either my Xbox 360 or my Xbox Series X I am no longer able to log into my xbox profile via 360 mode (on a backwards compatible game for example, like Perfect Dark Zero). When I try I recieve the following error:

Your console can't connect to Xbox Live. Do you want to exit this session and test your network connection? If you are playing a game, you will lose any unsaved progress. 8015190A

I have followed the Microsoft Support link, and tried the suggestions of changing my original xbox avatar via my Series X and changing my security information to confirm myself via my verification methods. This has not changed anything, and my issue remains.

I am no longer able to log into xbox via 360 services (which means I can not play 360 titles online or garner achievements). Screenshots to follow.

















I really could do with some support on this one.

:)