I probably watched this movie about 10+ years ago, language was English. I'm not sure if I've remembered all of this entirely correctly.
Movie starts out with the main character growing up in this picture-perfect little town. There are public announcement speakers in the town, and all is well except the main character's mother is always sick/almost comatose.
But weird stuff happens in the town. A sinkhole appears in one area of the town and swallows up a kid (perhaps leaving their tricycle?). The PA Speakers say there's nothing to worry about and say to avoid the area. The sinkhole then later just disappears.
Turns out that the mother who is always comatose is somehow keeping the town "alive" or structurally sound, and when she comes out of her stupor for a bit then the sink holes appear, but now she's getting old and so they're appearing anyway.
Can't remember much more, but think it might have been some dream that she and her husband cooked up to raise their son in the perfect environment, and I think in the end the main character decides that he has to make the sacrifice to take over from his mother?