Dell OM Nagios Plugin to monitor VxRail

Hello,

I am trying to monitor a VxRail cluster using Nagios Core. I have setup the Dell OM Nagios plugin on my monitoring server. The discovery utility works fine and creates a config file:
python3.6 dellemc_nagios_discovery_service_utility.py --host x.x.x.x --output.file "/usr/local/nagios/dell/scripts/" --force --prefProtocol=3 --http.user=nagios -http.password=yyyyyy

However, when I manually try to run the following check command, if fails:
python3.6 dellemc_device_check.py --host x.x.x.x --devicetype=IDRAC --componentname=System,iDRAC --protocol=3 --http.user=nagios --http.password=yyyy --http.port=443 --http.timeout=30 --http.retries=1 --logPath=/usr/local/nagios/var

The error is the same for all 3 protocols: SNMP, WSMAN and Redfish:
| ERROR | REDFISH: No response from remote host

So the discovery utilty works for all protocols (I can also do an snmpwalk of the iDRAC without problems), but the checks always fail with "No response from remote host".
I am running Centos7 and have installed Python3.6 next to the system's Python 2.7.4 which you cannot remove or upgrade anymore. The Dell scripts are called by python 3.6.
The VxRail nodes are P570F and the iDRAC firmware version is 4.10.10.10.
Does anyone have any clue as to what the issue might be?

Regards