I frequently see the Location icon in my menu bar despite not having any apps running that use it. When I click it, it says Maps is using my location, even when I don't have the maps open at all. Is this normal? Should I be worried about some kind of security issue?
Most probably it is significant locations, which might need maps to name the coordinates.
Significant Locations allows your Mac to identify places significant to you in order to provide useful location-related information in Maps, Calendar, Reminders and more. Significant Locations are encrypted and can’t be read by Apple. Click Details to view a list of locations that have been identified. You can select and remove locations from the list or click Clear History to remove all the locations.