Symfony version(s) affected: 4.4.18, 4.4.19

Description

In version 4.4.17 I overwritten the translation of the phrase Username could not be found. in the domain security.
In version 4.4.18 and 4.4.19, you cannot overwrite, the original translation appears.

How to reproduce
Create a file translations/security.en.yaml and insert the contents into it
Username could not be found.: 'The login or password is incorrect.'