I don’t really like Apple, but once in a while they do the right thing. This comes from the App store’s new labels on apps.
Signal just has “Contact info” under the “Data NOT linked to you” category. This is just the phone number + contact discovery.
UPDATE
There’s another post adding telegram here. This is what it looks like:
Check the signal app settings. The app should be allowed to use any battery it wants etc, many android flavors give it a battery restriction which inhibits signal from working in the background.
And the reason why should that matter for my desktop app is? If my phone is off won’t the desktop app run?