Since the last update of OSMC in my Raspberry PI I was unable to connect from my smartphone using this awesome app called FX Explorer on the other and I still can use Juiced SSH.

So I had to dig on that problem!

After I little search I finally manage to find the problem, the last version of OSMC had a different configuration
[cc_bash]
$ sudo vim /etc/ssh/ssh_config
[/cc_bash]

That was a missing algorithm in that line:
[cc_bash]
KexAlgorithms curve25519-sha256@libssh.org,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256
[/cc_bash]

Just add
[cc_bash]
diffie-hellman-group-exchange-sha1
[/cc_bash]

So the line looks like:
[cc_bash]
KexAlgorithms curve25519-sha256@libssh.org,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1
[/cc_bash]

Now save, exit and restart sshd service
[cc_bash]
$ sudo systemctl restart sshd
[/cc_bash]

And you’re done!