Automated triage: Cannot reproduce
Thank you for reporting this issue. The default member_about template uses the same variable name for the follower in both the loop and the avatar, and this hasn't changed since before 2.3.11. If you see a different name, it most likely comes from a customised copy of the template in your style or from an add-on's template modification.
This is an automated assessment. A member of staff may review and update it.