bad code replacing

Google translate:
Hello,
I would like to point out to you a very very penalizing bug for all the inhabitants of the French overseas departments. Indeed, we use a rather particular telephone system, because although we are all in France, we each have our own international code.
France is +33
But Martinique for example (where I am) is +596.
However, our French telephone system replaces this international code with a national 0.
My number is recorded in signal in international format + 596696xxxxxx
And when I receive a call from mainland France, signal transforms the 0 into +596 (which is my own callsign) but which does not necessarily correspond to the number of the person who sent me this message. The sender's number is therefore FALSE. And if I try to answer him, I must have an error.
To achieve this, I have to send my message by replacing the +596 with a +33 manually.
You will agree that it is far from very practical.
Thank you in advance.

No file or test is named. Start by reproducing the reported number transformation in Signal Android using a Martinique number receiving a call from mainland France, then trace where the sender number is normalized. Done means the sender retains the correct international identity and replies do not require manually replacing +596 with +33.