Go to the BP_HostNewGameServer widget and copy the video below.

Then create a new variable called MaxPlayers set the type to Integer and the Default Value to 99

Then create another new variabled called LastText set the type to Text and the Default Value to 10

Next copy the image below.

Go to the BP_HostLoadGameServer widget and copy the video below.

Then create a new variable called MaxPlayers set the type to Integer and the Default Value to 99

Then create another new variabled called LastText set the type to Text and the Default Value to 10

Next copy the image below.

To change the max player limit change the MaxPlayers Default Value on both the BP_HostLoadGameServer and BP_HostNewGameServer widgets.