А по-моему, вы не указали ни единого порта.
Попробуйте так:
sudo nmap -p- $HOST_IP
# nmap -v -p- 127.0.0.1
Starting Nmap 7.80 ( https://nmap.org ) at 2020-08-09 04:02 MSK
Initiating Parallel DNS resolution of 1 host. at 04:02
Completed Parallel DNS resolution of 1 host. at 04:02, 0.02s elapsed
Initiating SYN Stealth Scan at 04:02
Scanning 127.0.0.1 [65535 ports]
Discovered open port 22/tcp on 127.0.0.1
Completed SYN Stealth Scan at 04:02, 2.94s elapsed (65535 total ports)
Nmap scan report for 127.0.0.1
Host is up (0.000022s latency).
Not shown: 65534 closed ports
PORT STATE SERVICE
22/tcp open ssh
Read data files from: /usr/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 3.16 seconds
Raw packets sent: 65535 (2.884MB) | Rcvd: 131083 (5.506MB)