Sulani "thriving" but looks polluted

My sims cleaned up Mua Pel'am in Sulani and I received pop ups that it was "improving " then "thriving," but the island still looks the same. Trash still spawns every day, the water is murky, and there are areas of oil slick/pollution and dead-looking coral. I do get the turtle hatching event, but the island is still ugly compared to what it's supposed to look like (I had cleaned it up awhile ago but my computer had an issue and I lost my data). I tried repairing the game and deleting my caches. I don't use mods or ccs. Any help is appreciated!