Hi,
In the MapRun App, log out of Garmin, and then log back in. (in Options & Settings)
Make sure you log in with the same Garmin account as you are using in Garmin Connect for your watch.
If there are still problems, work through this document step by step, and email support@maprun.net with the specific step
at which you encounter problems:
https://maprunners.weebly.com/uploads/6/8/6/6/6866500/maprung_detailed_fault_diagnosis_v2.pdfPeter