I change the syndicate after the syndicate showdown.
When the syndicate showdown symbol disappeared I waited about 30 minutes to leave my old syndicate and request entry to the new one.
Next time when I logged in, I received a dialog box saying that I did not receive any individual price
I just saw a question mark!
Some hours before the end of the syndicate showdown I was at least somewhere in the ranking.
My assumption is that I changed the syndicate too early and lost my individual points...
P.S.:
I received a syndicate reward, but do not know whether it was achieved by the previous or the new syndicate as both fell into the same category of rewards...