Optimize-Hoppers.patch causes inconsistent behavior when hoppers collect Drops

Expected behavior

Hoppers should always check for and collect drops once per tick.

Observed/Actual behavior

If a hopper fails to inject items into its target container, it will no longer check for and collect drops every tick.

Steps/models to reproduce

1. Place some simple blocks.

2. Then drop any items at the water source, and you’ll notice that the hopper frequently fails to pick them up.

https://github.com/user-attachments/assets/fc6f2e1a-2f23-4fe4-af72-a613596cd2ba

Plugin and Datapack List

null

Paper version

paper1.21.8#49

Other

The configuration file is freshly generated and has not been modified.
Testing shows the issue is related to the hopper-cooldown-when-full option; setting it to false restores normal behavior.
This issue usually breaks dual-speed hopper sorting systems.

When a hopper fails to inject items into its target container, it should perhaps avoid entering a cooldown that skips the per-tick check for collecting drops. In the current situation, neither the chest nor the hopper itself is full.
When I tested the Lithium mod, no similar issue occurred.
Perhaps in the future we should find a way to preserve the hopper optimizations in Optimize-Hoppers.patch while reducing its behavioral intrusiveness so it behaves more like vanilla—just as Lithium does for hoppers—but this will probably be a slog that demands considerable time for testing.

Start by inspecting Optimize-Hoppers.patch and reproduce the behavior with hopper-cooldown-when-full enabled, then compare it with the option disabled. Verify that a hopper checks for and collects drops once per tick even when injection into its target container fails, without regressing the optimization.