@oldguy58 in GTS, Options-> Network and I believe the only option in there is to clear cache. We haven't really had the game long enough to know if it's needed before every online race (as we got into the habit of doing for GT6). In my opinion, a better way to go is giving your PS4 a dedicated IP address and then changing your router settings to put that IP address in the DMZ. We've also seen
@roamer2629 have this issue a lot, but I believe he got a newer router and did the DMZ trick and hasn't had the problem since.
EDIT: there's also some router port forwarding that you can setup that is supposed to help
Link, but I don't know of any WRS'ers (besides maybe
@JamCar0ne ?) who have tried setting that up.