I recently connected a Deco S4 (basement) a Deco x50-outdoor and a Deco E4(loft 100 feet away) I recently got a message that a web threat was blocked. No one in my household was using the wifi at that

I want to get wireless wifi out to the barn. From what I understand, I should get the x50 outdoor. Then, I'm assuming, I need another deco unit to link it to. I can get that far, but do I need to conn