i had the same issues of the trainer not working at first... but i got it working when launching the game and before the main menu shows i activate it and i changed hero when i was at the keep and it worked! try different things and eventually it will work and i can confirm also it does give loot at the end of matches!
Didn't work for me sadly, still activates and doesn't take effect.
I can confirm that it's working 100%.
Can you detail how you got yours to work as all the troubleshooting I did, did not seem to help me.