Opacity for multiple objects, displayed in wrong order (sometimes)

Hi there,

We have a model which is created in 3ds Max, representing an architectural development project. It’s styled in a specific way to put the whole project in one style.

For the vegetation we are using billboard planes with vegetation. They each have an alpha mask for the transparency.
In the viewport of 3ds max this looks correct, however when exporting this scene to an glb file and testing this in the threejs editor online.
It often happens that certain objects jump in front of the other, which is not the correct order of the objects.

Please let me know if you know the cause of this issue and how to mitigate / resolve this.
Thanks in advance
Pieter