Distracted while feeding

C

My 4 month old has always fed really well up until the last few days. She’s become distracted, unlatching and looking around. This happens on one breast in particular and sometimes she even back arches and squeals. The squealing doesn’t seem to be pain though because as soon as I sit her up she’s ok and if I lay her down on the floor she’s ok. Any suggestions or has anyone else experienced the same thing? I’m worried my supply is going to drop 😔