Cannot get device_tracker loading properly in split config

Hallo all,

I am trying to split my config up into different folders. My configuration.yaml has the following contents:

homeassistant:
  name: Home
  latitude: !secret latitude
  longitude: !secret longitude
  elevation: !secret elevation
  unit_system: metric
  time_zone: Europe/Amsterdam
  packages: !include_dir_named integrations

My integrations folder have the following files:

integrations
├── cast.yaml
├── circadian_lighting.yaml.bak
├── config.yaml
├── device_tracker.yaml
├── frontend.yaml
├── history.yaml
├── light.yaml
├── lovelace.yaml
├── map.yaml
├── mobile_app.yaml
├── mqtt.yaml
├── person.yaml
├── recorder.yaml
├── sensor.yaml
├── sun.yaml
├── switch.yaml
├── system_health.yaml
├── utility_meter.yaml
├── vacuum.yaml
└── weather.yaml

0 directories, 20 files

With device_tracker.yaml only containing:

device_tracker: 

With this setup, the device_tracker.see service is not available. It does become available when I edit my configuration.yaml to contain the device_tracker setup:

homeassistant:
  name: Home
  latitude: !secret latitude
  longitude: !secret longitude
  elevation: !secret elevation
  unit_system: metric
  time_zone: Europe/Amsterdam
  packages: !include_dir_named integrations
device_tracker:

I tried removing every entity I could and tried to eliminate what happens if I eliminate certain files. However, I could not figure out a pattern. Furthermore, if I run

hass-script check_config -c /path/to/config -i device_tracker

on the configuration that does not expose the device_tracker.see service. I get the output:

Successful config (partial)
  device_tracker:

However, I do not see the device_tracker being loaded in the logs when I run this configuration. So I am a bit stumped since all other stuff from the configuration seems to run fine. Is there something I am overlooking at the moment?