Not wanting to lay down 😣

My 6 month old has been giving me pure hell every time we lay her down. She just screams bloody murder until we pick her up, but once she’s calm and we go to lay her back down, she’s screaming as soon as she touches the mattress in her crib! It wasn’t ever like this before. It’s mainly for naps that this happens, but sometimes at bedtime too. She’s clearly tired but I don’t know why she’s fighting it. She is going through leap 5 in mental development so I don’t know if that’s for sure it or not but this is awful 😭😭😭