Caldigit TS3 Plus, Ethernet slot always showing cable unplugged, my OS Catalina

I purchased Caldigit TS3 Plus today and try to use it's network function on my 2018 mbp. Ethernet slot always showing cable unplugged.

I confirm my network is normal (I connected this cable to other computer and it works).

Tried below procedures but not working. A. Restart B. Download official drive from Caldigit (though not necessary),installed and restarted C. In network setting, hardware, set it to be manually according to some googled articles

I am supposing is it possible that not compatible with new OS Catalina? What can I do now?

I had a similar problem. I'm not sure the cause for the issue, but I agree that it seems to be related to the Catalina update. I can provide what worked for me, but I can't really explain why it worked -- I honestly can't even be sure that this was the cause for things to start working again. Given this, if I should move what I wrote to be a comment under the OP's question, then please let me know, or feel free to go ahead and do so.

I managed to get things working again by removing the Thunderbolt bridge and Thunderbolt ethernet slot(s) from the Network settings. I then installed the support driver (found here: https://archive.caldigit.com/KB/index.asp?KBID=179&viewlocale=1 ) It says that it's the Ethernet driver, but the part that I needed was the Support driver; in fact, the Ethernet driver install failed several times for reasons that are unclear to me. Once I got the USB Hub Support file installed, and I rebooted, the network preferences gave the option of a Thunderbolt Ethernet Slot, which I installed and it seems to work.

I recall that there was a Thunderbolt bridge before, but it doesn't seem to be needed now, so I wonder if something that was added/changed with the last OS update is the culprit. I will have to leave this those with more expertise than I have.

Good luck