Xbox One offers unlockable rewards which are embedded in every Xbox 360 game called Achievements. These Achievements are further classified as the traditional Achievements and special Challenges. While the system works fine, there may be times when you find that Xbox Achievements is not working properly. If Xbox Achievements and Challenges is not working, updating, showing, unlocking or popping up on the screen, then troubleshoot the problem by following these suggestions.
Xbox Achievements not showing
1] Check the Xbox Live service. It should be up and running.
2] Ensure that you are connected to Xbox Live and then try unlocking the achievement again. Press the Xbox button and select Achievements. Next click on See my achievements. A completed achievement may take up to 72 hours to show up. You may also sign in to your Xbox account at xbox.com, select your profile icon in the upper-right corner, and then select Profile. Next select Achievements > Title of the achievement. If it appears, it has been already unlocked.
3] Restart your console and see. To do this, press the Xbox button > Settings > Restart console. If need be, physically power off the console by keeping pressed the Xbox power button on the front of the console for 10 seconds. Wait for 10 seconds and then again press the power button to turn it On. Now allow up to 72 hours for the synchronization to take place.
4] If Achievements is not working on your Windows 10 Xbox app that you downloaded from the Windows Store, Run services.msc to open the Services Manager and ensure that the Connected User Experiences and Telemetry service is Started and set to Automatic.
The Connected User Experiences and Telemetry service enables features that support in-application and connected user experiences. Additionally, this service manages the event driven collection and transmission of diagnostic and usage information (used to improve the experience and quality of the Windows Platform) when the diagnostics and usage privacy option settings are enabled under Feedback and Diagnostics.
Hope something here helps you.