When doing arcgis enterprise maintenance and removing obsolete cache server directories I noticed a strange behavior. Dynamic services were dependent on obsolete cached server directories. I had to change the dynamic service cached directory to a valid directory, save and then restart the service. Dynamic services should not be dependent on cache server directories. I believe that these were applied automatically when the dynamic services were created or when the software was upgraded. Whether this is a bug for the current version of arcgis enterprise or an intended function, it does not make sense to have a caching tab active for a dynamic service. If the intent is to make it possible to convert the dynamic service to a cached service, perhaps there is a better way to do this.