I'd have to do some research to provide any specific information.  I can say that some USB MIDI controllers that connect to a PC rely on the PC's software to "set up" the controllers and do not work well apart from the PC.   One specific example is the Native Instruments Kontrol S MK series of keyboards.  They have lots of capabilities but living apart from a PC is not one of them.   So for these keyboards I would have to have the computer connected to both the Native Instruments controller and the keyboard (Reface in your case) at the same time and use the DAW or computer software to route the MIDI data between the two.

I can also say that I have a Novation MIDI controller that does work well apart from the computer because it can "remember" even advanced settings you set with the PC.  And so it works well as a general purpose PC-less MIDI controller assuming it has been setup properly.

I don't know, off the cuff, where the Remote LE falls.  My Novation is an MK SL series controller.   Last I looked there was a Novation support forum.   Even though someone (including myself) may provide more detail for your device here - I do think that the root of the issue is in configuration or capabilities of the Novation Remote LE.