Steps To Reproduce

sage: R=algebras.Free(QQ,('A','B'),degrees=(1,2))
sage: Rc=R.completion()
sage: A,B=R.gens()
sage: Rc(A)+1
1 + A
sage: Rc(A)**2
...
TypeError: unable to convert (A,) to a rational

Expected Behavior

This should return A^2

Actual Behavior

raise TypeError

Additional Information

No response

Environment

- **OS**:ubuntu 22.04
- **Sage Version**:10.3.rc4

Checklist

• I have searched the existing issues for a bug report that matches the one I want to file, without success.
• I have read the documentation and troubleshoot guide