I have a grayscale DEM. From the screenshots it can be seen that the min max value of the pixels range from 267 to 270. However from the generation report (using Metashape) it is known that the actual heights range from 241m to 275m. How do I make the pixels in the raster correspond to these actual heights and not some seemingly random values it has picked?
I had a similar SE-GIS question several years ago. The answer: by default, QGIS displays an estimate of the min/max values, which results in the unexpected values. To see this, open up the Min/Max Value Settings button, shown in your bottom screenshot.
To avoid the estimation, set the Min/Max Value Settings > Accuracy tab to Actual (slower).
For more detail and background, see the two (excellent) answers to my question at: