Q: Photos App / iCloud storage

I used the "optimize storage" option with my Photos library and iCloud. Now I switched back to "download originals" in order to keep my whole archive on my disk. It took some time until downloads were finished, but now it says it's done. However, the Photos library is around 35 GB, while iCloud shows around 110 GB of Photos & Videos. How is that possible and what can I do to make sure my whole library is stored on my disk (before I switched to "optimize storage" it used to be >35 GB, so I am quite sure the current library is not complete)?