I was actually testing with Windows 8.1 and IE11, so I'm pretty sure it's a setting somewhere.
Next thing I would try, go to
Control Panel\User Accounts and Family Safety\Credential Manager
Click Windows Credentials
If there are stored credentials under, Generic Credentials.
It will be called something like Microsoft_WinInet_(the IP of your device):80/admin@OBi110
Click the dropdown menu next to the name, and then the remove button.
Then restart Internet Explorer. If you want to be 100% sure, you can restart your computer.
Clicking remove while IE was open seemed to create this problem for me as you described, and then when I restarted IE it started working again, so I think this is at least on the right path.
If that somehow doesn't work, you can go back to the same place:
Control Panel\User Accounts and Family Safety\Credential Manager\Add a Generic Credential and type the ip of the device and the Username and Password and hit save.