SSL VPN username case matters?

I made a workaround that works for me in testing: https://devcentral.f5.com/codeshare/apm-ad-authentication-case-sensitivity-workaround-1191

Update: Oh, you had a user whose backend username was capitalized already; my workaround solves a different issue where the user mistakenly enters a capitalized username which caused kerberos authentication errors, but I'll leave it here as it might still be useful to someone.