It is not likely the cable but I suppose it could be. Issues with cables normally affect all application not just 1 particular one. You should see issue to very common things like speedtest or one of the ping test sites.
In any case it is a cheap things to try. They key to a quality cable is that it is pure copper (no cca) and have wire size 22-24 (no flat or thin cables). Cat5e is good enough it will run gigabit speed. You can but cat6 if you can get it cheaper but it will provide no benefit. Stuff like cat6a is used when you have 10gbit ports in your equipment still only runs 1gbit when your ports are only 1gbit so you pay more but get nothing extra for your average install.