So I did some research and ended up the same solution. I used the card with a m.2 to pcie cable, and at the beginning it shows up in the thunderbolt control panel but because I don't have a thunderbolt device to test and any regular type c device just won't work, I unplugged the card and it never shows up again. I've seen someone saying the card driver version after 23 won't allow jump wire, and mine is 50. I'm curious what version are you using and do you have issues using regular type-c devices or any hot plug issues?
I don't have the card anymore. It was between 10G SFP+ NIC and TB3. I use 10G more, so sold off TB3 card.
Only have a 10G to TB3 NIC(Which is already in another machine) and a external SSD as TB3 devices.