I think I’m running into this issue as well. Were you able to resolve in any way?
I need to use Send to Tableau Server daily, and it used to work well in the GUI, and batch mode, but something has changed and now it only somewhat works in the GUI, and not batch mode. In the GUI, it does fail 50% of the time with large files (same size). In batch mode, Task Scheduler times it out at 8 hours and exits.
Scott did mention that there is a ticket related to Send to Tableau Server, but I’m not sure if what you’re facing is the same issue as described there.