Bug on navigation with NavigationArea2D/NavigationAgent2D and TileMapLayer since Godot 4.5: target position never reached

[Datoh]

Tested versions

• Reproduce in 4.5
• Not reproduce in 4.4.1

System information

Windows 11 - Godot 4.5

Issue description

since Godot 4.5, the path computed with a NavigationAgent2D is not optimal (in Godot 4.4.1, the path is a straight line ) and sometimes the target position is never reached.

Steps to reproduce

• Open the attached project with Godot 4.4.1
• Run the project
• The red square goes directly to the target point
• Open the attached project with Godot 4.5 (migration)
• Run the project
• The red square is stucked

Minimal reproduction project (MRP)

bug-navigation.zip

[JDvideos]

Can confirm, I recorded two videos of the issue:
Godot 4.4.1 (working as expected):
https://drive.google.com/file/d/1h_o-w8ZDIWKn84KBOx8QxtEYcBJ2T1ex/view

Godot 4.5 (moving incorrectly):
https://drive.google.com/file/d/1ry0vRWHJ1xwrjZRzB3ud5-g6uuYnSGYD/view

[smix8]

ERROR: Navigation region synchronization error. More than 2 edges tried to occupy the same map rasterization space. This is a logical error in the navigation mesh caused by overlap or too densely placed edges.

Please do not ignore navigation map or region rasterization errors showing up in debug.
When edges are merged wrong or not at all due to layout issues the pathfinding will be broken, no exception.

You likely had the very same issue in Godot 4.4.1 but just did not notice because other edges were affected. The rasterization logic has not changed, only order has.

If the cause of that error is just tiny edges sprinkeled over the layout you can go to the ProjectSettings and set navigation/2d/merge_rasterizer_cell_scale to a smaller value. If the error does not go away even with the smallest value possible you have some navmesh overlap created somewhere.

[foohines]

Here's a MRP that shows the same or a similar issue, but doesn't raise any errors during navmesh baking or runtime.

It works fine in 4.4.1, but not in 4.5

Repo: https://github.com/foohines/godot-4.5-navigation-bug

Zip godot-4.5-navigation-bug-main.zip

Screen.Recording.2025-09-22.062134.mp4

[smix8]

Closing as the corridor funnel postprocessing bug is fixed with PR #110815 while the rasterization error mentioned above is still an issue that the project needs to handle. PR #110841 may help with this.