This feature works fine on Linux, but on the other platforms it lets you enter the server information but doesn't appear to try connecting at all (verified with tcpdump).
Tried with versions ranging from 22.214.171.124 to the 6.2 RC.
FYI I just duplicated this on Windows with the 6.2 Beta.
I have version 126.96.36.199 (x64) on Windows,
and can confirm that SSH and SMB are not working.
Also from 188.8.131.52 on Mac OS X, this functionality does not work.
Version 184.108.40.206. from Linux (Opensuse 42.3) is not working.
On all my systems I am able to get a connection using other tools like: ssh,putty,winscp
It works for me using the default Ubuntu 18.04 version:
I tried with protocols ssh, dav, and smb and all were successful.
Is this a duplicate of bug 98897 ?
Yes, this seems to be a duplicate of bug 98897.
*** This bug has been marked as a duplicate of bug 98897 ***