Have you paused syncing in Lightroom Desktop? Click on the cloud icon in the top right - at the bottom does it say Synced and Backed Up, or Sync Paused?
Do you see your edits from Lightroom Mobile getting synced over to Lightroom Web? Open Lightroom Web and check whether the images have updated with the edits you've made on the mobile app. Also, check the Sync Issues section in Lightroom Web and ensure there are no sync errors.
Make sure that Sync is Enabled on Lightroom Mobile and it is connected to Internet.