Unifi device tracker ignoring device - already exists - how can I remedy this problem?

HASSOS version 0.108.6, running on a Rpi 3.

I have recently switched my Unifi device_tracker in HA from the previous yaml setup to the built in integration using my Unifi controller. After that, tracking of my most important devices are not detected by HA anymore. According to the log, there are duplicate entities without unique IDs, so they are ignored.

2020-04-20 14:47:58 ERROR (MainThread) [homeassistant.components.device_tracker] Entity id already exists - ignoring: device_tracker.[device1]. Platform unifi does not generate unique IDs
2020-04-20 14:47:58 ERROR (MainThread) [homeassistant.components.device_tracker] Entity id already exists - ignoring: device_tracker.[device2]. Platform unifi does not generate unique IDs
2020-04-20 14:47:58 ERROR (MainThread) [homeassistant.components.device_tracker] Entity id already exists - ignoring: device_tracker.[device3]. Platform unifi does not generate unique IDs

Is there a way to remove duplicates and start over with discovery of devices?

EDIT:
I got them back by commenting out the entities in known_devices.yaml, but I would like to rename them and show a profile picture for each which I was able to do in known_devices.yaml before.

EDIT2:
Managed to rename them and add the profile picture through customize in yaml.

I am having the same problem as well.
I understand the first edit of your post, but can you please explain the second edit.
How did you rename them in customize.yaml
I am having trouble with how to format it.
Thank you Tomas.

Hi Carlton,

the names can be edited in HASS “Configuration / Entitites” and searching for the device_tracker in question, click on it and then change the properties. But better yet is to give them a friendly name in customize, like this:

homeassistant:
  customize:
    device_tracker.tomas_pro_5:
      friendly_name: Tomas
      entity_picture: /local/avatars/tomas-192x192.jpg

    device_tracker.cillas_huawei_p10:
      friendly_name: Cilla
      entity_picture: /local/avatars/cilla-192x192.jpg

Hope this helps!

Thank you Tomas, it worked perfectly.