`device_tracker.see` sets `source_type` to `gps`?

service: device_tracker.see
  dev_id: test_tracker
  location_name: home

The service creates/updates the device_tracker.test_tracker entity.

I’ve noticed the entity has Source: GPS (source_type: gps ) attribute → how so?

The GPS value is definitely “not true”…
How do I change it? What are the valid values (and what are they for)?

BTW, I’ve also noticed that the source_type is null after HA’s restart.

I see nothing about that in the docs: