mosh login to server stops right after showing the /etc/issue or says no data received or exit right away

[skygunner]

mosh 1.3.2 [build mosh 1.3.2]
both server and client are Ubuntu 22.04
firewall ports for 60000:61000 are opened both input output and on both machine.
nc can connect through.
Also the login shows the server's /etc/issue content.
ssh has no problem.
Is there a log can be checked to see what's going on?

here's the auth.log on the server side

Apr 12 00:14:23 hostn sshd[1793727]: Connection from 125.92.1.2 port 54704 on 10.0.0.212 port 1022 rdomain ""
Apr 12 00:14:23 hostn sshd[1793727]: Accepted key RSA SHA256:sha256keystring/QRmk/sha256keystring222 found at /home/userxx/.ssh/authorized_keys:4
Apr 12 00:14:23 hostn sshd[1793727]: Postponed publickey for userxx from 125.92.1.2 port 54704 ssh2 [preauth]
Apr 12 00:14:23 hostn sshd[1793727]: Accepted key RSA SHA256:sha256keystring/QRmk/sha256keystring222 found at /home/userxx/.ssh/authorized_keys:4
Apr 12 00:14:23 hostn sshd[1793727]: Accepted publickey for userxx from 125.92.1.2 port 54704 ssh2: RSA SHA256:sha256keystring/QRmk/sha256keystring222
Apr 12 00:14:23 hostn sshd[1793727]: pam_unix(sshd:session): session opened for user userxx(uid=1001) by (uid=0)
Apr 12 00:14:23 hostn systemd-logind[850]: New session 4034 of user userxx.
Apr 12 00:14:23 hostn sshd[1793727]: User child is on pid 1793732
Apr 12 00:14:23 hostn sshd[1793732]: Starting session: command on pts/1 for userxx from 125.92.1.2 port 54704 id 0
Apr 12 00:14:23 hostn sshd[1793732]: Received disconnect from 125.92.1.2 port 54704:11: disconnected by user
Apr 12 00:14:23 hostn sshd[1793732]: Disconnected from user userxx 125.92.1.2 port 54704
Apr 12 00:14:23 hostn sshd[1793727]: pam_unix(sshd:session): session closed for user userxx
Apr 12 00:14:23 hostn systemd-logind[850]: Removed session 4034.
Apr 12 00:14:34 hostn sudo:   userxx : TTY=pts/0 ; PWD=/var/log ; USER=root ; COMMAND=/usr/bin/cat auth.log
Apr 12 00:14:34 hostn sudo: pam_unix(sudo:session): session opened for user root(uid=0) by userxx(uid=1001)
Apr 12 00:14:34 hostn sudo: pam_unix(sudo:session): session closed for user root
Apr 12 00:14:59 hostn sshd[1793807]: Connection from 125.92.1.2 port 58408 on 10.0.0.212 port 1022 rdomain ""
Apr 12 00:14:59 hostn sshd[1793807]: Accepted key RSA SHA256:sha256keystring/QRmk/sha256keystring222 found at /home/userxx/.ssh/authorized_keys:4
Apr 12 00:14:59 hostn sshd[1793807]: Postponed publickey for userxx from 125.92.1.2 port 58408 ssh2 [preauth]
Apr 12 00:14:59 hostn sshd[1793807]: Accepted key RSA SHA256:sha256keystring/QRmk/sha256keystring222 found at /home/userxx/.ssh/authorized_keys:4
Apr 12 00:14:59 hostn sshd[1793807]: Accepted publickey for userxx from 125.92.1.2 port 58408 ssh2: RSA SHA256:sha256keystring/QRmk/sha256keystring222
Apr 12 00:14:59 hostn sshd[1793807]: pam_unix(sshd:session): session opened for user userxx(uid=1001) by (uid=0)
Apr 12 00:14:59 hostn systemd-logind[850]: New session 4035 of user userxx.
Apr 12 00:14:59 hostn sshd[1793807]: User child is on pid 1793812
Apr 12 00:14:59 hostn sshd[1793812]: Starting session: command on pts/1 for userxx from 125.92.1.2 port 58408 id 0
Apr 12 00:14:59 hostn sshd[1793812]: Received disconnect from 125.92.1.2 port 58408:11: disconnected by user
Apr 12 00:14:59 hostn sshd[1793812]: Disconnected from user userxx 125.92.1.2 port 58408
Apr 12 00:14:59 hostn sshd[1793807]: pam_unix(sshd:session): session closed for user userxx
Apr 12 00:14:59 hostn systemd-logind[850]: Removed session 4035.

on the client side, I don't find useful information