Looks like a veneer that was not glued properly. I would contact the manufacturer as it's probably a workmanship issue you may be able to take an iron to it to see if you can get the glue softened ,then hold firmly until bitbit put a cloth between iron and shelf to protect

Were these custom made? If so, get the cabintemaker out to take a look. They will likely have to be refinished off site and re-installed.

I would try the iron first and see This is usually a hot iron install edge so try it and if no luck then the guy who built them if they were custom .Looks like just the bottom one and right above a sink Could be a moisture issue.

Yes, custom made. I’ll tell the cabinetmaker to get back here and fix his shoddy workmanship. 🙄 They weren’t cheap - I’d expect better since it sounds like he didn’t do it right the first time.