If you only have the phone app then yes they are instantly downloaded and removed from their servers.

But if you have Desktop client(s) registered, then they need to hold onto those messages until you open your client(s).

That is why they have a 30 day login limit on Desktop clients. If they didn't they'd potentially have to hold onto messages forever.

https://github.com/signalapp/Signal-Desktop/issues/4730 https://community.signalusers.org/t/dont-unlink-devices-afte...

That seems like a problem.

But the solution seems to be to have the desktop client request data from the phone.

In fact I'm not sure how it can possibly work otherwise (what if someone just uses their phone for years and then opens the desktop client for the first time ever? does that not show any old messages? seems a terrible design).

Yes if you open the desktop client after 30 days its de-linked and you lose all new messages. And yes its bad design and very annoying, but understandable given their storage limitations. Have a look at the links I posted.

Retrieving from the phone would be a better idea I agree.