Netmiko telnet login failure issue on some devices

I have a netmiko script that works fine on some IOS devices but fails to login on others. Only commonality is the three routers that it fails on are Cisco 7206 on TACACs. The odd thing is both netmiko's debug and session_log shows it is entering the correct username and password (and I can log in manually) but it returns with login failed error.

Anyone else experiencing similar issue?

Snippet from debug:

username: DEBUG:netmiko:write_channel: b'xxxxxx\r' DEBUG:netmiko:read_channel: xxxxxx password: DEBUG:netmiko:write_channel: b'xxxxxx\r' DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b'\r\n' DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b'\r\n' DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b'\r\n' DEBUG:netmiko:write_channel: b'\r\n' DEBUG:netmiko:read_channel: