Items in water faster in Minecraft 1.13?

I just looked at a tutorial for an item sorter that works with water. There, the items were very slow on a surface that is not made of ice. For me, however, they are traveling so fast that they are not properly positioned. Is that due to the version or have I adjusted something?

You can't adjust anything. Water got a big update, I did not play regularly, but a lot has changed. Just search for an item sorter for your version. Hopper are always available anyway and are usually more precise.