Getting to the bottom of it: Remote Computer Management\Storage\Disk Management - SOLVED

Alternative: Open cmd prompt "as administrator" on the target server and on your local workstation.
1) Run the entire script on the remote server
2) Run the 1-line 'Volume" rule also on your workstation.

If you're in a domain, limit the rule to "domain profile" only, if desired. This script enables remote management of volumes, users/groups, scheduled tasks and event logs. Again: You will likely want to tweak it for just your domain profile; that's beyond the scope here. You easily can add RDP, file sharing, etc., as needed.

echo off
rem save this on the server as 'remset.bat' or similar
rem open cmd prompt with "run as administrator"
rem 
rem Allow remote management of a Windows server
rem On Every server, run this entire script - you can tweak to allow only for Domain profile, as needed.

rem - sets some remote mgmt abilities
echo "doing quick config wmi enablement"
echo.
call winrm quickconfig
echo "quick config done"
echo .

rem - allows disk / volume mgmt.

echo "doing remote volume mgmt enablement"

rem - WARNING, you MUST run 'remote volume management' cmd ALSO on your local computer that will be connecting to the server
rem     if you do not do this, then 'remote volume management' will not work from your PC to the server.

netsh advfirewall firewall set rule group="Remote Volume Management" new enable=yes

echo "volume management done, GO AND RUN the above netsh command also on your local workstation!"
echo.

echo "doing additional wmi enablement"

rem - allows some other pieces of the compmgmt WMI interface to work

netsh advfirewall firewall set rule group="Windows Management Instrumentation (WMI)" new enable=yes

echo "additional wmi enablement done."
echo.

echo "doing event log management enablement"
rem - allows event log and related mgmt

netsh advfirewall firewall set rule group="Remote Event Log Management" new enable=yes

echo "event log management enablement done"
echo.

echo "doing schedule tasks remote management enablement"
rem - Allows remote mgmt of sched tasks
Netsh advfirewall firewall set rule group="Remote Scheduled Tasks Management" new enable=yes

echo "scheduled tasks enablement done.
echo.
echo on

The above script enables some of the most common remote server management features via firewall rules.