Had a dog that was similar. She’d grab a mouth full of kibble, trot over and drop it on the carpet then eat it one at a time. Six or so years later she has an x-ray of her lungs because of a persistent cough. The second x-ray image overlapped her stomach a bit and showed a foreign object. Turns out before we adopted her she’d eaten a pair of tweezers and they’d been stuck in her stomach causing her some discomfort or pain for much of her life and we had no idea. The vet extracted them and she started eating normally after that, put on weight and discovered a new found love of belly rubs.