[BlackNitrogen]

If I understand your description, you reset your account. They delete the messages for safety when you reset. An attacker could reset by getting ahold of your phone number by sim jacking or the govt getting your text. It's a safety method so no one can take you texts. Of course many people want to carry their texts along, but this is a safety risk if you lost control over your number. So that's what signal is doing. If I recall when I had to reset my own number they did say they were deleting my old messages.

[Mediterraneo10]

Signal allows backing up messages (though the UI and workflow for it is still rather clunky), so you should be able to restore them even if you switch to a different phone number entirely.

[techntoke]

No, I had removed the app from my mobile previously, not deleted my account. When I resynced, they had removed my account and the messages saved on my desktop disappeared.

[sadfklsjlkjwt]

That is the same thing. The messages were stored on your phone never on any "account". The desktop was only ever a mirror of the phone. This is explicitly how Signal works. WhatsApp works the same way.

If you did not delete the Signal directory on your phone then there should be some old backups with your messages there. These will be encrypted so you will need to original password to unencrypt them.