Forward to Folder Broken After Saving Existing Proxy Host (Without Edits in NPM GUI)

[TritonB7]

I'm currently using NPM v2.9.7.

My Proxy Host is configured to forward https://gateway.domain.com to /guacamole folder at https://gateway.domain.com/guacamole/ folder:

My Proxy Host settings are:

Details Tab

• Domain Names: gateway.domain.com
• Scheme: http
• Forward Hostname/IP: 0.100.100.10
• Forward Port: 8080
• Cache Assets: Disabled
• Block Common Exploits: Enabled
• Websockets Support: Enabled
• Access List: Publicly Accessible

Custom Locations Tab

• Location: /
• Scheme: http
• Forward Hostname/IP: 10.75.100.10/guacamole/
• Forward Port: 8080
• Custom Nginx Configuration field is blank (Gear Icon)

Advanced Tab

• Custom Nginx Configuration field is blank

Problem:

When viewing the settings for my Guacamole proxy host and clicking the save button without making any changes, my Guacamole subdomain (https://gateway.domain.com) for the service no longer forwards traffic to the correct address (https://gateway.domain.com/guacamole/) and now loads a blank white page at https://gateway.domain.com, instead of the usual login page. However, prior to clicking the save button, the proxy host functioned correctly and would forward traffic to https://gateway.domain.com/guacamole/ as normal.

I was able to restore my previous instance of NPM from backup (same version) and started troubleshooting. I found that prior to clicking the save button, the following snippet of the working proxy host (nginx) configuration file was:

location / {
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-Scheme $scheme;
    proxy_set_header X-Forwarded-Proto  $scheme;
    proxy_set_header X-Forwarded-For    $remote_addr;
    proxy_set_header X-Real-IP          $remote_addr;
    proxy_pass       http://10.100.100.10:8080/guacamole/;
...
}

However, after clicking the save button (without making any changes to the settings in the NPM gui for the proxy host) I now get the following in the configuration file, which is no longer redirecting to https://gateway.domain.com/guacamole/ :

location / {
    set              $upstream http://10.100.100.10:8080/guacamole/;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-Scheme $scheme;
    proxy_set_header X-Forwarded-Proto  $scheme;
    proxy_set_header X-Forwarded-For    $remote_addr;
    proxy_set_header X-Real-IP          $remote_addr;
    proxy_pass       $upstream;
...
}

Anyone know the advantages/disadvantages of these changes that were made after re-saving the proxy host configuration, other than the obvious result in my case. I can get the page to load again by using the first code snippet, but I'd like to know more about these changes so I can understand why they were made and their implications.