Vibrating and shaking

The car was shaking when I turned the AC/heat on. it was the AC compressor and now it doesn’t shake when it’s on. but every now and then it’ll like vibrate and shake at a acceleration or deceleration even shifting gears. not sure if it’s a motor mount. the serpentine belt is fairly new. The motor doesn’t rigorously move when shifting gears it seems when I’m looking under the hood? Any ideas? Thanks, Charlie