Are you noticing that some locations are not showing up as an option to add to the map?
You may have clicked the Table of Contents button:
And then clicked on the Locations tab:
You probably have more in your list than shown here, but there is actually a limitation. There can be no more than 40 items in this list.
This is driven by the Map Group setting when importing a list of locations:
Essentially what that item does is allow you to categorize your locations to group them together as a layer on the map, based on a column in your list of locations. You can keep locations separate (i.e., your locations and competitors, or different facility types, or existing and proposed locations) and give each category a unique symbol style on the map.
If you import any combination of Location files and Map Group Field categories that exceed 40, they will not display. This could be 1 Location file with 41 categories or 41 individual Location files. Anything over 40 will not display in the Locations list in your Table of Contents in mapping (e.g., the second image above).