When I level up my character, any change I make to the Rolled HP value is not saved. I open the HP adjustment window and change the Rolled HP value, which updates the Total HP. I select Save, and while on the Class page the new Total HP is correct. But if I then go to the actual character sheet or if I refresh the page, it reverts to the old Total HP.

EDIT: Never mind, it randomly started working now.

Your problem was that I think you set the HP to Fixed not Manual. On the 'Home' section of the Character Builder, you will see the HP type, go there and click 'Manual' it will automatically be set on 'Fixed' but you can change it. Select Confirm after you have selected which type you want.

Quote from Nat_30 >>

When I level up my character, any change I make to the Rolled HP value is not saved. I open the HP adjustment window and change the Rolled HP value, which updates the Total HP. I select Save, and while on the Class page the new Total HP is correct. But if I then go to the actual character sheet or if I refresh the page, it reverts to the old Total HP.

EDIT: Never mind, it randomly started working now.

 There is an issue with the server’s internal cache. Next time it acts up like that, log out and log back in and that triggers the server to reset its cache. Then just wait about 20 minutes for everything to catch up with itself and try it again.