Clicks not registering in Unity

Hi,
I'm trying to make an AR mobile app.
The interface is in HTML and is served by a server. It communicates via Unity via EvaluateJS.

I would like to be able to click on the red area to place object in the floor (using a raycast).

The red area is transparent (I set the webview to transparent too) and I see the Unity world here.
The issue is that when I click in the red area, my click is not registered by Unity (in android) so it doen't trigger the placement of the object at this position.

I tried to use https://github.com/gree/unity-webview/tree/experimental/unity-over-native-ui and it seems to work in the editor but not in android. I also tried with 32Bit and RendeOverNativeUi enabled and disabled and it changed nothing. I know it is in experimental.

Am I missing something ?

Thanks a lot for the project and the help provided
Wishing you the best day

Start by reproducing the issue on Android with the HTML interface served by a server and communicating through EvaluateJS. Compare the experimental unity-over-native-ui branch with the reported 32Bit and RenderOverNativeUi settings; done means clicks in the transparent red area reach Unity and trigger placement at the tapped position.