@droftarts indeed, I inverted the wires and now it works, thank you!!

Hello everyone, we recently got a scanning Z probe for one of our 3d printers at work and I have to set it up.
I've read again and again the pages on the duet site on CAN connections, on the sZp and most of the forum topics related to the probe.
I added G4 S2 ; wait for expansion boards to start on the config.g file.
I have connected the wires that go from the probe's GND and 5V to the corresponding pins of one of the IO ports (IO_4) and the two wires from CAN-L and CAN-H from the probe to the RJ11 port on the 6HC, on the CAN1 connections, not the CAN0 ones as specified in the forum and on the CAN connections page but the probe's LED still flashes off sync with the main board.
Yesterday we've updated the firmware to 3.5, LEDs are still off sync.
Have I missed something in the connections? here's how they look:

now, with everything connected as shown, sending the command M115 B120 gives off this message: m115 b120 CAN response timeout: board 120, req type 6024, RID 0.
I've never worked with 3d printers so all of this is new to me and I have to spend a lot of time researching this stuff, so hopefully all of you with more experinece than me will see a blatant mistake and point it out to me.
Thanks to anyone who can help, it's really appreciated.