Did the problem start after the service or was it there before service? Check and make sure the fluid level is right at the top when warm, these things are picky about fluid level. There have been issues with either the wrong filters, bad filters, or failed installation causing issues when a service is done. The trans should not do that when going from R to D, or form D to R. If it started AFTER the service, it is likely an issue with the filter install. If it was there before service could still be a filter issue.