Something more than sleep regression?

I thought it was sleep regression but my LO is refusing to stay asleep in her bed. So, she’ll sleep but won’t stay asleep in her bed even though she has done it numerous times just fine. I just find it odd, she can fine in her bed one night but not fine the next. I don’t understand how the majority of the month of January I could rock her to sleep, lay her in her bed and she sleeps for 10 hours and now it’s barely 2 hours at a time. My butt has gone numb in the rocking chair too many times 🤦🏼‍♀️ Will this pass? It’s exhausting when you know she can do it but won’t. I’m worried it’s creating a bad habit but it’s not like I can do anything else.