Header param with underscore in http requests not available at server side when requesting via postman

Following is the curl export of the API call which is failing -

curl -X GET \
  'http://endpoint.in/dummy/path?mobile=777777777' \
  -H 'Content-Type: application/json' \
  -H 'auth_token: iubsaicbsaicbasiucbsa'

The header param auth_token is not available at all in the server side, as checked from logs.

The same curl however works when directly issued as a command. I have the latest postman version v6.2.3 installed. Also, the same API end point works when requested via other tools like Advanced REST client of chrome.

Previously, I had also checked read this thread http://nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers

Many servers, like nginx, have a config which if set, discards headers with underscore in name.

However, I could not verify the same because I could not find out exactly how is the server deployed in this. It is a node application and we run this command to run the application -

nohup /bin/forever start -o logs/out.log -e logs/err.log app.js

ps -ef | grep node shows the following -

root      5981     1  0 Jul19 ?        00:00:00 /root/.nvm/v7.2.1/bin/node /usr/lib/node_modules/forever/bin/monitor app.js
root      5991  5981  0 Jul19 ?        00:00:04 /root/.nvm/v7.2.1/bin/node /usr/local/another/path/to/app.js

Update

This is interfering in our automated testing as well, via Jmeter.

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