My url & display name keeps changing back to a number even after personalising both with my names numerous times. How do i ensure that this doesn't keep happening?

Question

Almost very time I load a page while signed in on Microsoft learn, be it the page to verify my certification or just opening up the dashboard, I will notice that at the top right corner of the page where my profile icon should appear with my initials it instead appears with a number. I have to change this every time to make sure name & not that number is what shows on my documents. This also affects the url to my profile which I had personalised with my names because it also keeps changing back to a number, meaning this breaks all links to my profile or verifiable achievements.