6 month old sleep schedule

Hi mommas- we sleep trained my almost 6 mo old (on Wed) around 3.5 months so she was going to bed on her own no hassel. We start our routine at 6p, shes usually down by 645ish. She wakes 1 or 2x to feed and usually goes back down no problem. She wakes up anytime between 5-630. We try to get her up no later than 645 to take her to daycare. The past week or two she has been a bear. Screams for hours at a time when we try to put her down. After an hour I go in and calm her and put her back down. Then she rolls around and plays with her feet. Is she going to bed too early? Is this part of her leap? We're going nuts over here because I know she's tired. She loses her mind around 545/6 which is why we start bedtime routine. Sidenote: She naps about 30 min in am and anywhere from 2-3 hours in the afternoon. I try to give her about 3 hours wake time before putting her down at night. Thoughts? Suggestions?