This may be the reason why you are not seeing the Developer Notes.
Developer Notes do not display for additional Admin accounts you create in PowerCMS.
Those accounts are intended for an end-user or client and aren't expected to be adding code to pages. However, the Developer Notes should show for all content areas if you are logged in as the Super Admin.
Still, if you want us to take a look at your issue, we'll need to be able to log in.