I'm not sure, but by chance did you tinker with manually editting any of the configs (i.e. tabsvc.yml)? If so, this may cause such problems, and it's much more predictable to go through the prescribed path when adding workers. What I would suggest to do now is to a complete uninstall and then start clean.
I also found another thread where the solution was to disable extra Network Interface Cards (NICs) on the computer where Tableau Server is running, if those NICs are not available for use: