Hi, let's see if we can sort this out together.
You say Octatrack is routed to all inputs except it's own. Do you mean outputs?
Can you give me a portwise description of the routings at play? in a format like this:
Port 1 IN: Octatrack -> out to
port 1 OUT Polybrute
USB port A OUT port
etc.
Port 2 IN: whatever
NDLR does pass MIDI info to its outputs, but it does so according to some set rules which allow you to choose whether or not you want to use that feature without having to make any menu selections. This info can be found on page 33 of the manual here:
https://conductivelabs.com/wp-content/up...l-v1.9.pdf
but basically NDLR DIN Port A IN is connected with DIN A OUT and USB 1, and
DIN B is connected with USB 2, so if I want to send MIDI to the NDLR but not have that passed THRU Then I would only route MIDI from the NDLR ports 3 or 4. There's really no reason to use more than 1 NDLR virtual port (that I can think of) so you're not likely to need more than that 1.
The only Port for USB MIDI going to the NDLR is port 1, since there is only 1 USB out on each USB host port, so anything passed to it will come back out port 1 OUT. If we only route from 3 OUT then those notes will be blocked. Same with 4 OUT.