Quick answer: Apply your own wind force to rigidbodies in the wind region each FixedUpdate, scaled by exposed area and gusting, since WindZone never touches rigidbody physics.
Grass and leaves sway in a WindZone while a dropped leaflet or balloon ignores the wind. That is expected: WindZone is for visuals and cloth only, not rigidbodies. You must apply the force yourself. Here is how.
How to fix it
1. Apply wind force manually
For each rigidbody in the windy area, call rb.AddForce(windDir * windStrength * exposedArea) in FixedUpdate. WindZone provides no rigidbody force, so this is the only way physics objects feel it.
2. Add gusting
Modulate the wind strength with Perlin noise over time so the push varies in believable gusts rather than a constant uniform shove, matching the look of the WindZone visuals.
3. Scale by drag area
Give light, high-drag objects (paper, balloons) a larger area factor and heavy objects a smaller one, so wind tosses the light things while barely moving the heavy ones.
Catching the ones you can't reproduce
The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.
Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.
This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.
Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.