Trail ruins disappeared

Started collection of all the pottery shreds. Completed 2 trail ruins a few months ago, returned to complete the sherd collection, but cannot find trail ruins. I have used a seed map for finding structures and can verify coordinates, including the 2 done previously, which are still existing. I have gone to the location of 5 different trail ruin locations and have not been able to find the ruins. I have experience in locating them from a previous realm, so i am certain that something happened that no longer creates the ruins.