We're aware of reports that access to Signal has been blocked in some countries. As a reminder, Signal's built-in censorship circumvention feature might be able to help if your connection is affected:

Signal Settings > Privacy > Advanced > Censorship circumvention (on)

We have already started working on more advanced censorship circumvention techniques, but in order for these efforts to be most effective we need the big companies who are dragging their feet on moving away from plaintext SNI headers to start taking this problem more seriously.
Solutions like Encrypted Client Hello (ECH) remove the plaintext server name from the TLS handshake, which makes it far more difficult for hostile ISPs to block access to the sites and services you care about — but this isn’t widely supported yet. We hope that starts to change.
In the meantime, our team will continue to do everything we can to maintain and restore access to Signal. We appreciate your patience and support.

@signalapp
You are barking under the wrong tree. The first and immediate problem is your weird dependence on phone number during registration. SMS is not encrypted and those "some countries" don't need to do any mumbojumbo to block #Signal, it is simply enough to block the registration SMS!! We have been telling you this for about 3 years now, and you did absolutely nothing about it.

And yes, I'm a monthly donor to Signal !

@Mehrad @signalapp Am I crazy or aren't they rolling out a username system to address this?