There are several causes of trails not showing on the map for a region you have downloaded.
We have had some issues in the past with region downloads, so the first step is to delete the region (state, province or country) the trails are in and re-download that region.
First to delete the offline region data, which contains all the trails, pois and sub-regions follow the below steps.
Go to downloaded regions
Swipe region item to the left to reveal red "remove" button.