Delayed upload to iCloud library

A few weeks ago I had the problem with photos. If I took a picture and then wanted to edit them nothing was happening. Only the loading circle appears and that was it. Later that day this problem disappeared but from that day I have the problem with uploads to the icloud library. Before that, it took second to appear on icloud.com, but now it takes day or two. It is very strange as I didn't change any settings on my phone and I don't think it has to do something with my internet connection because it is happening at work, home etc...

Does anyone know what to do?

Thanks.