Sims 4 - Weird Trees

I have this too. Every single tree in Riders Glen is flat, but in some worlds none are. My graphics are on ultra, game runs smoothly. It's a new problem as of the Horse Ranch patch.

I'm not posting here as a first resort, but as a last resort. I've taken all mods out (I have very few), that made no difference. I've deleted the options.ini, so the game could recompile that, which made no difference. I've cleared the cache many times, repaired the game, even fully deleted the whole Sims 4 folder in My Documents, made no difference. Graphics drivers are fully up to date. I've got a new Ryzen apu, which has more than enough horsepower, but I wonder if the way it allocates memory is something that confuses the game.

Sometimes I'll load into the world, and for a tenth of a second the trees are full 3d, and then go flat. In many worlds, all trees are fine. In some worlds, it's the background distant stuff and doesn't really matter. In Riders' Glen, it's every tree and shrubs that's flat. It's unplayable. In the top desert neighbourhood, everything loads beautifully. Again, this is on ultra graphics and the game runs smoothly.

@luthienrising Without mods