Please be more specific.

When you first open the screen?
When you press the save button?
When you switch tabs? Which destination tab?
When you select a field? Which field?
When you expand a tray of fields? Which tray?

Every user? One specific user?

A few seconds after I hit the edit link. The periodic content reviews is expanded, my dob was filled in as 23/04/2017 and I cannot hit Save if I change anything.

admin user

Clearing the cache fixed it, I changed username from admin to webmaster on both sites. Only had that issue on 1 of them.

Does sound like a corrupt cache somehow, couldn't reproduce.