The next 1.1.5 hotfix to be released will have a fix. however it requires you to make a change to your code.
If you are connecting to an actual telnet server (like an rPi) you will have to specify the terminal type to use. Currently we only support VT100, and that should be good to telnet into most servers, if there is a need for another term type, please let us know.
Example existing connection code:
telnetConnect('192.168.1.100', 23, 'username, 'password')
New connection code:
telnetConnect([terminalType: 'VT100'], '192.168.1.100', 23, 'username, 'password')