Here's what a few people have told me that they've tried, and I just saw that the 50X50 lot Oakenstead, a house in Willow Creek does that with tiles. Oakenstead is the lot at which most people have posted was a problem. The tiles just disappeared for me, too, when I just tried it at that lot.
Here are a two screenshots with captions about how I fixed the problem.
Here are some of the tiles on that lot disappearing --- after I bulldozed the lot.
Then, I made a pool without walls or pool trim, etc. that covered the entire 50X50 lot.
Finally, I deleted the pool, and none of the tiles disappeared when I placed the tiles I wanted to cover the lot.