SSL_ERROR_SYSCALL and gnutls_handshake() failed - SSL/HTTPS are failing [Ubuntu Server 18.04]
This is usually due to your anti-virus software. Some anti-virus software wants to man-in-the-middle connections to "secure" your data and will block connections it cannot insert itself into. Since most Windows anti-virus software can't handle the Linux ELF executables, your connection fails.
Generally you want to remove such anti-virus software completely (disabling it may not be enough) and just stick with Windows Defender.