Unexpected Shutdowns

Hello everyone. I’m having problems with my iPhone 7 Plus. I bought this phone a couple months ago and these past two weeks it keeps shutting down on me at high battery percentages... usually when I’m watching videos on YouTube. I received a settings message saying it’s because the battery was unable to deliver necessary peak power so Peak performance capability has been enabled but it hasn’t helped. Maximum capacity is at 94% so i don’t think I need a battery replacement but I also don’t see what else could be causing the problem. I have done a DFU reset and that didn’t help either. Again, I bought this phone not too long ago so I’m confused on what could be going on. Any suggestions? Could it be I dropped my phone and the battery got loose somehow?