An update on this as I spent a lot of time going around in circles trying to resolve this.
I did have an Azure account which I had no idea I had created, I never used it and was unaware it was an account on my PC.
In resolving this issue, I tried signing out of the Azure account everywhere, but this did not work as I now had an error message in File Explorer insisting I log back in.
I tried logging in with my personal account, but this was rejected as it was a personal account.
I uninstalled the update, yet the new file explorer was still in place when the uninstall was completed. This shouldn't have happened as it should have returned to the old file explorer.
I went into settings > accounts, and the other account I did not want or use was listed in "accounts used by other apps", it would not let me delete the account from there. Bad show Microsoft...
I then had to go to settings > accounts > Access work or school account and then could remove the account from here. Point of very frustrating note - this inability to click an account and remove it from the menu, app, or setting that you are at is exactly why I cannot get to grips with IOS, and it is really disappointing to see this style of global settings start appearing in Microsoft products.
This still did not work, I tried a reboot, and the login request disappeared which was a sign of progress, but still no quick access.
Tried re-installing the update, but it still didn't work
I then cleared the quick access cache from the customdestinations and automaticdestinations and finally, the quick access reappeared and allowed me to select my quick access files
Hope this helps anyone else stuck