Hi anonymous user
As per my test, I reproduced this issue when I first create a page with a template:
Then two pages appear: One of the page is with random name.
If the template page exists or you add a page without using a template, you will not meet the case.
I would suggest you open a service request in Microsoft 365 admin center to confirm it with Microsoft.
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.