Howzit,
I just got my first gaming rig 2 or 3 months ago specifically to play BF 1 multiplayer and one thing I have learnt is that you should not buy premium because the premium servers do not fill up and the premium players ignore the other premium players requests to move\join a premium server.
For reasons I do not understand I always seem to be 100th in queue with premium priority when joining the normal 64 player conquest servers, but when I ask in the game chat "who has premium" nobody seems to have it as they claim they cannot afford it. I'm a bit mind boggled because my premium priority either doesn't work, or the premium players are not interested. IT IS REALLY SAD TO SEE PLAYERS GIVE SALT ON THE CHAT WHEN ASKING THEM TO JOIN A PREMIUM SERVER AS WELL.
I have since played 1 operations game on a SA operations server. It was lucky and probably a one time experience.
I have noticed that on weekends, mostly Sunday afternoons and in the evening the operations server tends to fill with some people. Most cases there are not enough players, but that's your best bet: Sunday 4pm and onwards.
Cheerz