[Disclaimer: there is a very slim mathematical chance that everything is okay, i just broke the world record]
Finding them in the random desert maze, from extensive experience (i know all areas like the back of my hand + don't linger + has done the sandswept ruins writ many many times) should take from 1 minute to 30. 45 if quite unlucky. 1 hour if super mega unlucky or something dragged you down.
My current character: can sneak when too many fights, deals with every fights easily, and me as a player, i'm so fed up that i'm just running from area to area. I'm saying that to say that i'm not playing "normally", at that point i was just trying to have super high map turnover to find the ruins. We're talking an average of 2 map transitions per minute.
So, 75 fire berries later (!!) I've been trying to find them for 3*1hour at that pace (or almost, the first 45 minutes i was playing normally). I say 3*1 hour because because i gave up 3 times (it's really not like me). So we're talking 3 hours of intense area transitioning in gameplay areas that are mostly empty (can't respawn). There's bound to have an issue? Right? Please say yes xD
I asked another fellow in the desert, he said he hasn't seen those ruins in a while. But I did the writ like 3 days ago... I don't see why you would have touched something within the two last days but... I would advise giving it a glance. As for me, I gave up on the writ
.Cheers (and sorry for the rant... it's been taxing on my sanity)