This might seem like a silly question, but I want to rule it out - in the commands you pasted above, when you ran them I'm assuming you changed out all the example text for the real user information in your environment, rather than using the exact commands above?
thanks for your answer! Yes, I changed all the example text for the special company information, just didn't want to write them down here
Sorry about the delay! I suggest opening up a case with Tableau Tech Support - they can take a deeper look at your logs and see what is happening. It looks like the Kerberos TGT either isn't being issues, or isn't being sent to the database, they'll have to check why not