Fortnite random players in team matches?

Hey I've been playing Fortnite on my phone for a long time, but for the past few seasons, if I'm not in the lobby with any of my friends in the lobby, I don't get random group members and it is not really fun to play alone in team matches (or duos) . Can someone help me (I have already switched off the childproof lock). Would be really grateful.

When you play the mode, there's an option called "do not fill up" or "fill up". You just have to choose to fill up

Thanks I'll try it out soon.