The BIGGEST issue right now I am finding with backstab is the fact there is NO indicator on the ground as to whether or not I am directly behind an enemy to stab.
This, the game is so finicky about where damage will qualify for backstab. I end up wasting like 3 AP every turn trying to get in the exact position required. Even if you appear to be directly behind them, if you are not 100% exact it will not allow you to backstab. This is with using B to go overhead to try and position myself.
It can be quite frustrating.
