@daughtersisterpartnermom This is completely random, but there was a different breed of dog that I remember seeing that had difficulty eating in the normal prone position. (your vet will be familiar with this condition, I mean the medical name which I cannot remember.)
The owners had created a special feeding chair that the dog essentially clambered into so that he was sitting upright when he was eating. That helped the food to go down with gravity and everybody was happy that way (and the food stayed down...
![Smirking face :smirk: 😏](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f60f.png)
)
You might want to see if you can arrange to hold your dog upright and give it some food as an experiment, just a little bit, and then see if it stays down after that feeding approach?
Worth a try, and free at least at first, aside from the extra effort.
As others have noted, this may also just be some sort of food sensitivity or allergy that you need to work through to ID.