signal-desktop can't connect to server

I just installed signal-desktop from the official repo, everything went fine with the installation.

Whenever I open it, I get the message that it failed to connect to the server. It doesn't give me much detail, just 'Something went wrong' and 'Failed to connect to server'

When I run it from the terminal, I do see 'x-attr dependency did not load successfully'

'debug log' – https://rentry.co/yzqnc32i – shows Signal is failing while opening the HTTPS/WebSocket connection.

Running 'curl -Iv https://chat.signal.org' shows 'SSL certificate problem: unable to get local issuer certificate' and 'curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.haxx.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.'