On any server with Refresh cycles Imagine the base below. Player is busy at work, with family, whatever, so he’s irregularly logging in to refresh his base, but he’s not actually leaving his castle. The blue figure represents the owner’s toon. The blue bubble represents the owner’s “render range” … the distance at which his game client draws and updates blocks, reading from the server. The game doesn’t render everything all the time because… well… that would be expensive on server resources.
Because the owner has logged in, and has loaded structure blocks, those blocks all get a decay timer update - reset to the maximum duration. Those would be the darker green blocks. Give or take a few blocks since I am only speculating at how the block rendering and updating actually works.
The pale green blocks are NOT refreshed and subsequently decay, and then auto-decay. Leaving our Owner very upset as a good portion of their base has disappeared. Thus why the Admins openly state please walk about and move to each corner of your build to PROPERLY refresh all timers.