Hi, just tried with juiceSSH from my mobile phone (external provider network) and works fine with redirect of open port of my router to port 22 on osmc.
Have you seen No SSH access from external net with putty ?
That time it figured out someone/somewhat has hijacked the user’s box.
Could you post your sshd_config? Command is paste-log /etc/ssh/sshd_config and provide the returned URL, here.