M4100 doesn't seem to work properly

Hello,

Disclaimer: I work in IT, but I'm definitely not savvy when it comes to networking.
I can understand concepts and technical lingo, but I'm just not used to dive into networking appliances, so my ordeal may very well be related to my lack of knowledge...

I have a M4100-D12G (firmware 10.0.2.30) which doesn't appear to be willing to play ball.
From my understanding (skimming through the manuals), Ezconfig is a good way to start a proper configuration.

Since I don't have a DHCP set up (and don't intend to), I connected via usb, and did set up an IP address, but I'm not sure it went as planned.
First roadblock: when its configuration is over, Ezconfig tells me that typing "show running-config" would display the final configuration.
Here is all I get:

(M4100-D12G) >show running-config
                   ^
% Invalid input detected at '^' marker.

"running-config" isn't even in the list I get from "show ?"

Here's what "show network" gives me:

Interface Status............................... Down
IP Address..................................... 192.168.10.80
Subnet Mask.................................... 255.255.255.0
Default Gateway................................ 0.0.0.0
IPv6 Administrative Mode....................... Enabled
IPv6 Prefix is ................................ xxxx::xxxx:xxxx:xxxx:xxxx/64
Burned In MAC Address.......................... xx:xx:xx:xx:xx:xx
Locally Administered MAC address............... 00:00:00:00:00:00
MAC Address Type............................... Burned In
Configured IPv4 Protocol....................... Manual
Configured IPv6 Protocol....................... None
IPv6 AutoConfig Mode........................... Disabled
Management VLAN ID............................. 1

Plugging any cable (from my current working switch) won't bring any led up, while they do get lit at boot.
The interface status is always "Down", and I couldn't find any way to bring it up.
I also can't log in to "enable", even though I did set its password (I get an "Authentication Denied. Invalid user credentials!" error).

I can access the boot menu, and even enter the config mode (through the "Password Recovery Procedure"), some other options just don't do much...
For instance, the Diagnostics Application requires a password I couldn't find.

I did a factory reset, to no avail.

All I need for the time being is for the switch to actually act as such, all the while having a management IP address I could connect to, rather than using the usb connection.

Any help would be appreciated.