Mosaic to new raster not adding all cell values

[GuyCochrane]

I have four 8-bit rasters. I calculated statistics for each raster. They do not have colormaps. Each raster has the same value scheme (80 unique values) but none of the individual rasters have all the values.  There is some overlap and I need to get statistics for how many cells there are for each value, without counting the overlap cells twice. I used mosaic to new raster to combine them. But the result doesn't have all the values found in all four rasters. So, for example value 13, and 14 are missing in the output even though those values are in one of the rasters.  I tried all of the colormap options even though the input rasters don't have a colormap. How do I get a single combined raster with all the values?

[DanPatterson]

are the missing values spatially random or do they occur in the areas of overlap?

[MingzhenChen]

Did you use seamline to generate (copy raster) new raster?
Display the raster sort by seamline. Make sure the pixel which you want to be in new raster is shown. If not, please try different seamline or edit seamline to make the pixel is used in new raster.

[CodyBenkelman]

Guy

did you check the environment variable for resampling method?  

https://pro.arcgis.com/en/pro-app/latest/tool-reference/environment-settings/resampling-method.htm

Usage notes

• The nearest neighbor option should be used for categorical data, since no new values are created.

Be sure to use nearest neighbor.  If your 4 rasters are not perfectly aligned at the pixel level, the software will resample pixel values.

If this doesn't solve it, could you look at pixel values between input and output and give us a specific response e.g. "lower right pixel in the input (last pixel at lower right) has pixel value 13, but in output it's 15..."

Cody B.