I feel you dude. I sat at a sign for 3 hours before some rando walked up and relocated a house on it.

This system is so broken.
Eitherrr..
-Have a timer that's visible so people can just show up for the mad rush then got on with their lives. Won't be selling houses still if the rest of the server has a couple hours to show up to contest for the plot.
or
-Give a randomly starting... lets say hour long... 'window' of time that it can open and make this time window visible when it happens. Then if you're gonna camp a plot you'll know its going to open within like an hour at least whenever it shows that its window has started
or
-Put house relocation on the current timer so people with pre-existing houses can't snipe new buyers and you don't have all this goofy 'run around until you have an open plot to relocate it to the one you want' sillyness (the fact that this is a thing just shows how bad this setup is)
or
-Literally anything else. I'm just firing off the first bad ideas that come into my head without considering the consequences, surely the game devs can think up something better