@Itati I am getting the same 33-504 error when trying to connect the hub through ethernet.
EDIT: I actually got mine to update following the instructions in Troubleshooting SmartThings Hub 2018 and Aeotec Hub. However, in addition to just blocking port 123 UDP I had to block all traffic to any ntp.org addresses. On an ASUS router it was achieved this way.
After this I did a factory reset on my hub (IM6001-V3P22) and added it through SmartThings. The hub updated and got added to my home.