Steps to reproduce:

1. Go to "Site administration / Server / OAuth 2 services" and create a new dummy service called "IMS Global" (you can use incorrect values).
2. In Site admin -> Badges -> Manage backpacks
3. Create a new backpack with the following details :
   • Backpack API URL - https://dc.imsglobal.org/obprovider/ims/ob/v2p1
   • Backpack URL - https://dc.imsglobal.org
   • API Version - Open Badges v2.1
   • OAuth2 services - IMS Global
4. Save changes
5. Edit the backpack you've just created.

Expected result

Field "OAuth 2 services" has the selected "IMS Global" oAuth service.

Current result

Field "OAuth 2 services" is empty.

I've been able to reproduce it in 3.9 and master.