Dell TB16 doesn't work correctly with downstream Thunderbolt device

So, I have an interesting problem. I am trying to digitize DV videos from my camcorder. My current setup is:

Apple Thunderbolt 3 to Thunderbolt 2 adapter -> Apple Thunderbolt 2 to Firewire 800 adapter -> Firewire 800 to DV cable -> PV-GS90P camcorder

This works if I plug it directly into the Thunderbolt port of my XPS 15 (9560). However, if I then run it through the TB16 Thunderbolt dock, the Thunderbolt 3 to Thunderbolt 2 adapter is detected, but the Thunderbolt 2 to Firewire adapter is not (no IEEE 1394 controllers show up in Device Manager). I have a fully updated BIOS (1.7.0) and the latest Thunderbolt Controller driver (16.3.61.275).