2hp MIDI Eurorack

[Darryl]

That's not a USB host port, its a client port for connecting to a PC's host port. It won't power anything. That module is specifically a PC to CV interface as there is no 5 pin DIN input.
Generally, if The NDLR USB cable can't plug into it, then its the wrong type of port. The exception might be with a USB C port, but that's a can of worms.

There are some MIDI to CV eurorack modules with a USB host port. Look for the USB Type A socket on them and they are probably labeled "Host". You can of course also use a cheaper MIDI to CV that has a 5 pin DIN input.

The NDLR has 4 USB virtual MIDI I/Os which, while being "class compliant" might confuse a less robust USB host. YMMV, I would stick with 5 pin DIN which also offers better timing.

Yes, i also have an Eloquencer with EME expander but NDLR does not power up when i connect it via USB.
I wish it had another way to power it.

I would think that EME expander would power NDLR. USB 2 spec says a host port must provide 500mA, and NDLR is less than 100mA. An unpowered USB hub might only provide 100mA but NDLR should still power if nothing else is consuming it all. As an experiment, you could try a powered hub in the EME and see if NDLR comes on. If it doesn't, something else is wrong.