So I decided to set up a horse riding school in new pack, and bought the Lighthouse Lookout lot in Nordhaven and gave it the Wild Prairie Grass and Heist Havoc challenges. Playing with mods, no prairie grass had appeared after about a game week, so I decided to test without mods and started a new save, setting up the Lighthouse Lookout lot the same way (Wild Prairie Grass and Heist Havoc) with mods disabled, and again after a game week there was not prairie grass on the lot. Previous experience was that prairie grass would start appearing after one game day.
I next started a new save without mods and only the Wild Prairie Grass challenge on the same lot, and let it run a couple of days, and no prairie grass spawned. I then started a new save with just the Wild Prairie Grass challenge in Hay Hill Landing in Ravenwood and 3 patches of Prairie Grass spawned, so it seems there's something about the Nordhaven world (or, at least, the Lighthouse Landing lot) that prevents the prairie grass from spawning.
Version 1.113.291.1020 DX11.
Edit By Crinrict: Adjusted Title fit migrated bug report: [NEEDS SAVES] [HR] Wild Prairie Grass Lot Challenge not spawning grass | EA Forums - 11630536
Archived thread had around 44 me toos
Don't think we need a separate report for Nordhaven.
