I've had this exact thing happen with my 2012 15" retina. Won't lay down flat and clicking the trackpad required pressing really hard. Had the battery replaced,

I've had this exact thing happen with my 2012 15" retina. Won't lay down flat and clicking the trackpad required pressing really hard. Had the battery replaced, works like new now — on Mojave, I'm not updating to the dumpster fire that is Catalina.