I checked all the usual suspects, NGW, Hi-Desert, Mototech Eng and a few others, no luck. But Stryker has them for back order. 4-6 weeks. But Stryker could take longer if shipping their lowers is any indication. The pin is the same for the 16 and 17.
I have some spares for my SCARs, but not a cam pin. Have you checked with the guys on the FN forum? Sometimes a member will part with a spare.
I’m guessing you are seeing the usual cam pin wear. Or has it failed? My SCARs have several thousand rounds on them and my pin wear has not changed much since the first 500. I do keep it well lubed.