[openssh-server] kex_exchange_identification: Connection closed by remote host

Using your openssh-server via Synology’s container manager on my NAS. I’ve set the required variables, and I’m using PUBLIC_KEY to pass my pubkey. I can find the properly formatted pubkey I supplied in /config/.ssh/authorized_keys. /logs/openssh is empty (no current log file). I’ve set my PUID and PGID, and I’ve defined a USER_NAME. SUDO_ACCESS and PASSWORD_ACCESS are both set to false.

When I try to ssh in using ssh -i id_rsa -p 2222 myuser@mynasIP from my windows PC (where I generated my key), ssh returns:
kex_exchange_identification: Connection closed by remote host

Not sure how to troubleshoot it, especially since there’s no log. Any suggestions or tips welcome. I’m hoping it’s just something stupid I’m missing.