Sleep regression? Separation Anxiety?

My LO has been STTN since about 6 weeks old. The last 5 weeks her sleep has gone to crap. She will go to sleep in her crib at first and sleeps around 5/6 hours but wakes up inevitably around 1am. (She has set her own bedtime around 630/7pm). On that 1am wake up, she isn't really hungry but has to be rocked and will fall back asleep but will wake up when put back down. It doesn't matter how long we rock, she will always cry when put down. We have tried stepped soothing, patting her back, you name it. 1 hour into attempting to get her back to sleep in her crib, we just end up taking her down to the couch and trying a bottle and she will sleep laying next to us on the couch. I'm hoping this is a phase but wondered if anyone has any tricks that they can suggest. I tried putting a blanket in with her and that didn't make a difference. I was hoping it was a regression and would pass but I'm scared we are creating another problem by taking her downstairs and sleeping with her. Any help is greatly appreciated. I want my good sleeper back.