How to reproduce: From a water source, ave a hole/lowering of a block 2 blocks away from end of water (10 blocks away from source). Note that updating the water by placing/removing anything around it does not affect the propagation, it cannot deviate from trying to get the hole it can’t reach.
Expected result: To keep propagating to the sides if the water cannot travel downwards somewhere.
Actual result: the last 4 blocks of water will not propagate to the sides and aim towards a hole. Only if the hole is 3 blocks away from the end it will propagate. Updating the flowing water does nothing if the hole is 2 blocks away.
I have seen this behavior in 1.18 and before. Didn’t see a bug report so I made one