It’s a home environment; it runs on the same network with 0 firewall settings anywhere.
I’m able to SSH into the Pi just fine,
user@ubuntu:~$ ss -tlnp
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 4096 0.0.0.0:27017 0.0.0.0:*
LISTEN 0 4096 127.0.0.53%lo:53 0.0.0.0:*
LISTEN 0 4096 127.0.0.54:53 0.0.0.0:*
LISTEN 0 4096 *:22 *:*
user@ubuntu:~$ ip addr list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 2c:cf:67:2e:a5:1e brd ff:ff:ff:ff:ff:ff
inet 192.168.1.214/24 metric 100 brd 192.168.1.255 scope global dynamic eth0
valid_lft 54718sec preferred_lft 54718sec
inet6 fe80::2ecf:67ff:fe2e:a51e/64 scope link
valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 2c:cf:67:2e:a5:1f brd ff:ff:ff:ff:ff:ff
user@ubuntu:~$ ps -aef | grep [m]ongo
mongodb 885 1 0 Jun20 ? 00:11:16 /usr/bin/mongod --config /etc/mongod.conf