Was this issue resolved ? I had similar issues. I did put 3 gauges on the TC to check what is going on. There was enough pressure but not enough flow ! Main issue was the filter in the gearbox, I did also replace the filter which sits between the TC and the pump. Last but not least, check correct oil ! If you have oil for the summer, it wont work in cold temperatures (until you heated it up to normal temps).
Also I cant see in your post that you mention if this is the TC or the Gear. If you look at the shaft between TC and Gear, if that does not run with high RPM when revving up, you have the TC issues above.