Sorry for the late answer, but I'm very busy (as usual).
Are both adapters connected to the same can bus?
Does both adapters work in readonly mode at the same time?
Why did you compile the driver from github? (Kernel 4.4 typically contains the driver.)
Maybe you should subscribe to
linux-can@vger.kernel.org mailing list and repost your issue there.
PS: Sadly I cannot test, because I have only one adapter.
best regards,
Bernd