I have downloaded latest Hub (2018.4) and Upsource (2018.2) from jetbrains website.
I have successfully configured both a gentoo machine with https access and Upsource accessing the external Hub.
I have followed the same steps to replicate the installation on Ubuntu 16.04 (with all updates) and have both software start without issues. I am able to access Hub on the configure port (8443) but when i try to access Upsource i get a connection error from browsers (ffox 65, chrome 72, safari) stating SSL_ERROR_NO_CYPHER_OVERLAP
I have analyzed the connection with wireshark and both TLS Client Hello offer the cypher: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (0xc030) but in the case of Upsource there's no Server Hello but a simple Handshake Failure.
In both cases (gentoo and ubuntu) the certificates used are the same for Hub and Upsource and generated as per jetbrains instructions
The only difference i can think of is the distribution but then, why i am able to access Hub but not Upsource?