Sideways currents in source water where there is no flowing water

There are strange sideways currents in water in 1.14. I noticed it when raiding an ocean monument. Under the sloping stepped ceiling that goes all the way around the monument, I kept feeling like I'm stuck in honey. Currents would always be pinning me to the walls. It felt different to my experience in 1.13.

All the water was source water, so there was no reason for this current. Previously, source water would only have a current if it has 'flowing water' next to or under it.

I built this simple apparatus to in 1.14 and 1.13 to compare the water flow. Waterlogged trapdoors verify that all the water there is source water, (since waterlogged blocks are always sources).

Here, in 1.14.2,  you can see the items are pushed to the side channel and end up in the hopper. 

And here, in 1.13.2, you can see the items simply move up and down.