RHEL7 "Too many authentication failures for", MaxAuthTries has no effect

I'm using Kitty (putty clone) and Keepass agent (similar to pagent). Keepass agent contains 5 ssh keys. This setup works fine with all linux boxes I've encountered so far, connection to our new RHEL7 linux box fails with type 2 (protocol error): "Too many authentication failures for ..." I added MaxAuthTries 6 to /etc/ssh/sshd_config and did a systemctl restart sshd.service but the error remains.