the X2 is not the X2.1
so what is true for the X2 might be irrelevant to the X2.1, and vice versa
X2.1: here you need to swap the wires in the CAN connector, as you say.
X2: here the PCB is routed incorrectly such that the CAN transceiver can’t work, and if one wants to correct for that one needs to do some delicate soldering. Since this is not something many would do, it effectively makes the CAN on the X2 non-functional.
the X2 thing is irrelevant to the X2.1, and hence OT. I just mentioned it in response to your question, thinking that it may help clarifying the situation. Sorry if it rather added to the confusion.
for the X2.1 holds (and that’s all I wanted to bring to attention):
it has CH and CL reversed on the CAN port
=> needs to be addressed by swapping around the CAN CH and CL wires on the CAN connector
(unless you connect it to a CAN device with the same reversed layout LOL ;))
EDIT: it’s kind of sad since, if you read e.g. Mike Kelly’s posts on UAVCAN, one of the appealing aspects to him is the simplified standardized connection … this practical advantage is a bit broken into pieces
EDIT2: paragraphs 2-4 here: UAVCAN: CANbus for the rest of us