not detecting some diffie-hellman kex algorithms

[IV2KBMoFxYIA]

an nmap scan for a server shows

Not shown: 822 closed tcp ports (conn-refused), 177 filtered tcp ports (no-response)
PORT   STATE SERVICE
22/tcp open  ssh
| ssh2-enum-algos: 
|   kex_algorithms: (12)
|       curve25519-sha256
|       curve25519-sha256@libssh.org
|       ecdh-sha2-nistp256
|       ecdh-sha2-nistp384
|       ecdh-sha2-nistp521
|       diffie-hellman-group-exchange-sha256
|       diffie-hellman-group16-sha512
|       diffie-hellman-group18-sha512
|       diffie-hellman-group-exchange-sha1
|       diffie-hellman-group14-sha256
|       diffie-hellman-group14-sha1
|       diffie-hellman-group1-sha1

shows on sshscan as

[+] Detected the following ciphers: 
            chacha20-poly1305@openssh.com        aes128-cbc                           
            aes128-ctr                           aes192-cbc                           
            aes192-ctr                           aes256-cbc                           
            aes256-ctr                           blowfish-cbc                         
            aes128-gcm@openssh.com               cast128-cbc                          
            aes256-gcm@openssh.com               3des-cbc                             


    [+] Detected the following KEX algorithms: 
            curve25519-sha256                    ecdh-sha2-nistp25                    
            curve25519-sha256@libssh.org                                              


    [+] Detected the following MACs: 
            umac-64-etm@openssh.com              umac-64@openssh.com                  
            umac-128-etm@openssh.com             umac-128@openssh.com                 
            hmac-sha2-256-etm@openssh.com        hmac-sha2-256                        
            hmac-sha2-512-etm@openssh.com        hmac-sha2-512                        
            hmac-sha1-etm@openssh.com            hmac-sha1                            


    [+] Detected the following HostKey algorithms: 
            ssh-rsa                              ecdsa-sha2-nistp256                  
            rsa-sha2-512                         ssh-ed25519                          
            rsa-sha2-256                                                              


    [+] Target SSH version is: SSH-2.0-OpenSSH_7.4
    [+] Retrieving ciphers...
    [+] Detected the following weak ciphers: 
            aes128-cbc                           blowfish-cbc                         
            aes192-cbc                           cast128-cbc                          
            aes256-cbc                           3des-cbc                             


    [+] Detected the following weak KEX algorithms: 
            ecdh-sha2-nistp25                                                         


    [+] Detected the following weak MACs: 
            umac-64-etm@openssh.com              umac-64@openssh.com                  
            hmac-sha1-etm@openssh.com            hmac-sha1                            


    [+] Detected the following weak HostKey algorithms: 
            rsa-sha2-512                         ecdsa-sha2-nistp256                  
            rsa-sha2-256                                                              


    [+] Compression has been enabled!

Notice that the diffie-hellman-group1-sha1 and others like it do not show on the sshscan output.