How to solve the routing problem?

Most of the time when the wayfinding is fine, but sometimes the wayfinding point will have a large deviation.I suspect that is why I keep updating the mesh.
error :
error

true:
true

I have used the funnel plugin.

Hi

Sometimes paths on navmesh graphs can be quite suboptimal, especially with very thin triangles. It looks like you have a Navmesh Cut with the number of edges set to a quite high value. I would recommend reducing the resolution of your navmesh cuts to maybe 6 edges (so each cut is a hexagon). This may improve the quality.

You can also use the beta version in which the funnel modifier has some improved logic for fixing deviations like this.

See also Using navmeshes - A* Pathfinding Project