Puppy going backwards in crate training?

My puppy is 5 months old today and I feel like he is going backwards in his crate training. He used to go in there and not cry at all and loved his crate. Lately he has been whining basically the entire time he’s been in there. He sleeps in there fine at night but when we leave or sometimes put him in there for naps he will whine the whole time. This is new. We know he is teething because of his constant bleeding all over but dang this is a bummer feels like we’re going backwards. Anybody else? Does it get better? So sad cuz he was amazing about his crate now he’s constantly sleep deprived 🙁