I found this while running the ansible tests of vyos_firewall_rules: https://github.com/vyos/vyos.vyos/pull/407#issuecomment-2774775677
Paramiko is the default on Ubuntu, when just using apt install ansible-playbook with ansible-galaxy install git+https://github.com/vyos/vyos.vyos.git, so I guess this is widespread.
I don't know the exact cause for this issue with zero bytes, but the fix is quite easy.
PR is here: https://github.com/vyos/vyos.vyos/pull/409