Many wood flooring problems are moisture or installation related. Many others are manufacturing or site related. Problems may look similar. Cause can differ in a variety of ways. The Cure is not always the same. You may need a wood flooring inspector.
In their book, Problems, Causes and Cures, the National Wood Flooring Association discusses and shares image of many different concerns.ProblemsCauses-Cures-2018-eddtion