Water Flow Fails to Apply Force to Items on Surfaces with Shallow Submersion (≤2 Pixels) in Beta 26.0.27

Description:
In the latest beta version 26.0.27, a regression has been introduced where water flow fails to apply movement force to items (entities) that are only partially submerged. Specifically, if an item rests on a block surface where the water layer above it is 2 pixels or less in height (e.g., lecterns, chests, sideways grindstones), the water will visually interact (showing submerged particles and extinguishing fire) but will not impart any horizontal or vertical flow force to move the item. Items only begin to be affected when the submersion depth is increased to approximately 3 pixels (e.g., on an end portal frame). A related issue occurs at the termination point of water flows when items are minimally submerged.

How to Reproduce:

1. Shallow Water Test:

   • Place a lectern, chest, or sideways grindstone in a water source or flowing water.

   • Drop an item onto the surface of this block.

   • Observe that the item shows water particles and can be extinguished but does not move with the water flow.

2. Deeper Water Test (Control):

   • Repeat the test using an end portal frame (3-pixel height difference).

   • Observe that the item does move normally with the water flow.

3. Flow Termination Test:

   • Create a 8-block-long horizontal water stream flowing over end portal frames.

   • Drop an item into the water at the start; it should move for the first 7 blocks.

   • At the 8th (terminating) block, observe that the item stops moving entirely despite being in water.

Observed Result:

• Items partially submerged (≤2 pixels) show water interaction particles but receive zero kinetic force from water flow.

• Items require approximately 3 pixels of submersion to be moved by water currents.

• At the end of a water stream, minimally submerged items lose all momentum and stop, breaking expected fluid dynamics.

Expected Result:

• Water should apply movement force to items regardless of submersion depth, as long as the item is in contact with the water block.

• Even shallow water layers (1-2 pixels) should impart flow momentum consistent with deeper water.

• Items should not lose all movement force at the termination point of a water current if still in contact with water.

Additional Notes:
This bug severely impacts many item transportation and collection systems designed by the Bedrock Edition community, as these often rely on precise water flow mechanics over partial blocks. The regression suggests a change in the fluid physics calculation where force application now incorrectly depends on submersion volume or collision box overlap, breaking previously functional redstone and farm designs. Immediate attention is needed to restore consistent water physics.