My dog has problems eating

Has a vet excluded any health-related causes? Like teeth, throat, stomach.

What about the floor? It looks like something with the ground is not OK for him. Did you try, to feed him in another room with a different floor?

I would feed him somewhere else and maybe warm the food slightly to make the smell more noticeable, and maybe add some cottage cheese! Also, the porcelain might not be the right material for the smell! And a different surface would be good, too. Perhaps the floor's glue is giving off something that's not noticeable to your nose, but definitely not healthy!

Try watering the food some time before you feed. Some food is very hard and therefore some dogs don't like it.

This behaviour is an old instinct, he tries to bury his food for later, because he is full for now, but doesn't want to waste it.

Yes, my Dog has this instinct too. Don't worry about this. In the video he buries his pig's ear

And if the cupboard is closed, the dog will steal a cleaning rag to hide the food.😄😄😄

I agree with Sina and Evi. If the dog doesn't lose weight, I wouldn't see any problem.

He wants to make a hole to keep the eating save in the ground for later because he seems to has enough perhaps. Or you have perhaps drugs under the floor and he is a retired police dog. Or he has seen the video of the motivated Dackel digging holes.🤣

Perhaps the food is not good for him and he wants to digg it to make it more wet. Give him perhaps wetfood when he has problems with the teeth perhaps so that he cannot bite dry food.