What strat are you using? I was able to beat it prior to the buff, but I have done a lot of testing post SLKR buff and can still consistently beat it.
Make sure Rey has a minimum speed of 501. Any lower, and the raiders will go before you and possibly one shot someone.
What's your roster? Make sure you have someone who can heal. That's been RH Finn for me. Depending on my team, I might use Lifeblood on him.
I used Rey, BB8, RH Finn, and RH Poe and all of my variations. When unlocking, I only used C3PO as the last slot. But my post SLKR buff testing has used RJT and Holdo in that last position too. If I use RJT, I use Lifeblood on her and the event special to make her taunt.
My strat has always been to focus down SLKR before taking out the adds. I know some people swear by using WW on the adds when available, but I didn't find it necessary. It worked both ways for me.