In previous versions, minecarts were able to go up an incline and eventually ride back down the rail way. In snapshot 19w11b, this is no longer true. If a minecart is launched up an incline it will not come back down. This is even true with powered rails and a block blocking the cart from continuing. The only way to get the cart moving again is by manually moving it. This seriously inhibits the ability for automated systems using Minecarts, as even with powered rails activated, they will not follow a decline unless moved manually.

I created a short video to demonstrate this issue.