your configuration for stream logging looks correct. Have you tried enabling traceoptions (debug) to pinpoint potential issues?
set security log traceoptions file stream-debug
set security log traceoptions flag all
Also remember that stream logs are sent by the PFE, not the RE - so the log collector has to be reachable via a revenue port. And source-address should also be on the PFE (not a management interface).
I just tried creating a stream where the receiving host does not answer on port 514 which gives a clear error:
user@fw> show log stream-debug | match SYN
May 15 08:24:40 rtlogd: miscellaneous string(len=107)=Connection error flaf Error code: major 3 minor 1 code 110, description:TCP time out after SYN is sent out
Let us know if this makes you able to get your tcp logging working as expected.