Calculator adds an unwanted additional decimal separator

Problem:
Every time the user inputs a decimal separator for the keyboard, an additional separator is input in the calculator. This bug has been detected using Elementary OS 5.1 with the French locale.

Example:
Typing '2,8' makes the calculator display '2,,8'
Typing '2.8' makes the calculator display '2,.8'

This bug makes the calculator do wrong operations:
2,,8 + 2 = 3,6

Or blocks it:
2,.8 + 2 = nothing, blocked with a warning ('.' is not known)