Steps to reproduce:
1. Open the attached project "Case_1223096"
2. Navigate to Project-> Assets and select "animales2"
3. In the Inspector window press "Sprite Editor"
4. In the Sprite Editor window click and drag to create new Sprite
5. Change its name
6. Create another Sprite
7. Select the newest created Sprite and notice that older created Sprites is selected

Expected results: Differetently created Sprites are separate
Actual results: Sprite is attached to another Sprite in Sprite Editor when Sprite is created after another Sprite is created and named

Reproducible with: 2019.3.0f5 (44796c9d3c2c), 2019.3.3f1, 2020.1.0a25, 2020.2.0a1
Not Reproducible with: 2018.4.18f1, 2019.3.0f5 (31004ce75319)

Note: It is crucial to have Sprite Mode selected to "Multiple" in the Inspector window of a Sprite to reproduce the issue