"load and keep original" does not load my photos

Hello, a while back i enabled the optimized storage option for photos on my iphone. now that i wanted to clear up my icloud space i enabled "load and keep original" in settings>[my name]>icloud>photos about 2 hours ago but it does not load my photos, i still only have the low quality place-holders and most photos still need to load. i googled this before but there were only like 3 people asking this and there weren't very helpful answers. so my question is if the process of loading all the photos actually takes several hours or do i have to do something to help? i already tried loading photos manually but this would also take hours and i don't know if this is just temporary or not. so could anyone give me any advice? thank you very much in advance:)