Thanks a lot for this immediate answer !
I reduced the size of the loaded textures to 25% of the original size. The visual quality is slightly reduced, but still acceptable (at least to be viewed on a smartphone). The assets are now approx. 30 Mb. Is this too much ?
Unfortunately, the problem is still the same: puzzle related interactivity is not working on android device.
Could you please be more explicit about possible problems related to camera logic ? I’m only using the camera position to initiate the starting point of view. Should I use it more ?