When decorating my Qeynos house, on KD, I had real issues with what I call, "decoration creep." I would place items, look at them from several angles, and find them perfectly placed. Later, I would enter the house, or enter with another character, and items would have moved slightly making them look out of place. I know this can happen if you move items once they are placed, but these were items freshly placed. So Bambee's Qeynos House, on KD, may, or may not, look "polished," depending on whether the items continue to creep. I also had items that would not place no matter how hard I tried. This usually involved something being placed on a wall. For example, I could place one Draconic Runed Sconce but not the second one. It seems there are some areas of walls that won't accept decorations, or just certain decorations. And the last issue I had was with the Highhold rugs. I put them in a home depot, bought from the Marketplace, and that somehow slapped a Lore tag on them in the Qeynos house. That became a real problem when I went to empty the depot so I could pick it up when I was finished decorating. This was on KD, so I don't know if it affects the rugs on other servers. When I put the rugs back in the crafting hall, home depot, the tag disappeared on all the rugs.
Yeah I've noticed the "shifting"f placed house items for years in my homes. Sometimes it's horribly bad and has to be fixed while other times it "shift" back correctly. This seems to mostly happen in my older Qeynos/Freeport house. I Do have a guildmate who has been complaining for years about placed items being "eaten" by the house or guild hall. Only way to retrieve the item is using the collect an item option at the front door and scroll through a Loooooong list IF you don't recall the exact name of said eaten item.
The house "eating" things and the "will not place in this spot no matter how hard you try" are both specific to that house type, and nothing has been changed with the older house types in years and years. If you can narrow down specific locs in specific house types, you could put in a /bug, but I have no clue what the to-do piles for the artists are like.
I have had items totally move from where they were placed after I listed them on the Leaderboards. It is frustrating to run through several times to make sure things are NOT out of place or alignment and it looks great, but after you put it on the Leaderboard and go through it you find a ceiling tile or a floor tile with a gap that is obnoxious or a window that is far from where it originally was placed and you cannot "fix" it. You decorate an area, leave the zone, return and it is not how you left it. Really frustrating and disheartening. But that hasn't stopped me from finding another place and doing it all again.
