Something interesting today: trying to label from a field with coded domain values. The value in the field is, say, 1, but the domain description is "Asbestos Concrete". The labels find the description when my data is in a file geodatabase. But in SQL Server SDE, it only labels with the actual field content. I have a call in with Esri on this, but I have a hunch it's a bug.
Found a solution! (Thank you, Esri support.) In Catalog, go to the mosaic dataset, right mouse for properties, Defaults tab, change Max # of Rasters per Mosaic to be larger than the number of your source images (the default is 20). And change Max # of Records Returned per Request to a ludicrously large number, like 100000. They didn't know why it helps... but it did.
huh? how did the mosaiic max # of rasterst config change labeling properties lol pretty sure the FC in your OP is vector not raster. What am I missing here lol
Were you able to resolve the labeling issue with coded domain values, I seem to be experiencing the same thing with 10.5.1