Can't add a script as a component when there are two classes with the same Name (one is a MonoBehaviour, the other isn't) in the same script , but in different Namespaces

Reproduction steps:
1. Open "PROJECT TO IMPORT ASSETS.zip" project
2. Try to add the "BreaksParser.cs" script as a component
3. A pop-up appears "Can't add script"

Expected Result: Script is added as a component as it has a valid MonoBehaviour in its second Namespace
Actual Result: Can't add a script as a component when there are two classes with the same Name, but in different Namespaces

Reproduced with: 2020.1.0a12, 2019.3.0b10, 2019.3.0b9, 2019.3.0b8, 2019.3.0b7, 2019.3.0b5, 2019.3.0b4
Did not reproduce on: 2019.3.0b3, 2019.3.0b1, 2019.3.0a1, 2019.2.12f1, 2018.4.12f1, 2017.4.34f1

Warning:
Class BreaksParser can not exist in multiple namespaces in the same file, even if one is excluded with preprocessor directives. Please move these to separate files if this is the case.

Note:
The issue doesn't repro in 2019.3.0b4 if last opened version was lower