SSO Isn't working after upgrade

We've been trying to test the latest version of UR in our sandbox, but have encountered issues with Single Sign On after the upgrade.

I looked into it, and the SSO cookie is being set, however the system is still prompting users to log in.

I did a side-by-side comparison of the sso_user cookie between our active version of UseResponse and our testing version.

The active version's (decoded) cookie is as follows:

{"source":"example.org","fullname":"test_user","email":"test@example. org","user_id":"1","redirect":"0"}

The sandboxed version's (again, decoded) cookie is a little different:

{"source":"sandbox.example.org","fullname":null,"email":"q5n4f4z4g4n4w5l4q4","user_id":"test@example.org","hash":"54","redirect":"0"}

It looks like perhaps the values are getting swapped around? Any advice you could offer would be appreciated, thanks.