1 - im coming from a grails (3.0) project and have the same issue. UUIDs work just fine until you put hibernate spatial on the classpath and using the postgis dialect. Unfortunatly none of the work arounds listed anywhere work and any settings in @column and @type or mapping = {} blocks are ignored and non-identifier UUIDs will be mapped as a geometry type. Interestingly identifier UUIDS are still fine. It was a big enough bug that it caused me to have to abandon my whole feature for now.