Tag not monitored by Microsoft.
Hey there, Sally Canbay
Please can you try turning your PlayStation console off completely and clearing its local cache. Once you have done this, please turn the console back on and try linking your Microsoft account in the game again.
Hopefully, this will allow you to link the account. In terms of this question, I am going to apply the not monitored tag, as this question is out of scope for this community. To get help and support for this type of question, please try the Forza Support team here: https://support.forza.net/hc/en-us
Please let me know how this goes & hope this helps,
Nathan