We found what was causing the issue on our end at least. Seems like the View Applications Pages permission was turned off.
We did this back in the day because we didn't want users to access with read permissions to Site Contents and Site usage.

To access this page, you can go here: https://yourtenant.sharepoint.com/sites/SiteAddress/_layouts/15/editrole.aspx?role=Read
Replace yourtenant with the corresponding value and replace SiteAddress with the Site address for the site in question. If not, you can access from here:

Then click on Advanced permissions settings, go to Permission Levels:

And click on Read

From there, you should be able to modify the role permissions.
According to the Microsoft agent we got assigned, this is an incident on their side. Since it was working fine with this setting before.
Hope this works for you.