8 weeks and drinking less???

My 8 week old has been having a really hard time staying awake during a feeding lately. I noticed it this past weekend. She will eat and stay awake for the first couple ounces, but ounces 3-5 are a struggle. She used to gobble the entire bottle before sleeping. Anyone else have issues keeping their kiddo awake while feeding?? Tips and tricks would be much appreciated too ☺️