Getting disconnected from Zero Build Duo matches each time the player count drops to 14-15

Downloaded Fortnite for the first time on this PC and joined an Xbox friend to play Zero Build with them. We noticed that for each game we played, I was disconnected from the party and game as soon as the total players dropped to 14-15 -- this occurred for all four games we played, like clockwork. I have an ethernet connected to my PC and my partner was able to continue playing, but I needed to rejoin the party after being booted back to the main menu.