try this

Jenkinsfile

@@ -12,10 +12,12 @@ def retryWithDelay(int maxRetries, int delay, Closure body) {
 def device(String ip, String step_label, String cmd) {
  withCredentials([file(credentialsId: 'id_rsa', variable: 'key_file')]) {
  def ssh_cmd = """
-ssh -tt -o ConnectTimeout=5 -o ServerAliveInterval=5 -o ServerAliveCountMax=2 -o BatchMode=yes -o StrictHostKeyChecking=no -i ${key_file} 'comma@${ip}' exec /usr/bin/bash <<'END'
+ssh -o ConnectTimeout=5 -o ServerAliveInterval=5 -o ServerAliveCountMax=2 -o BatchMode=yes -o StrictHostKeyChecking=no -i ${key_file} 'comma@${ip}' exec /usr/bin/bash <<'END'
 
 set -e
 
+export TERM=xterm-256color
+
 shopt -s huponexit # kill all child processes when the shell exits
 
 export CI=1