Hi,
I'm sorry to hear that you are experiencing these issues. This is likely related to recent changes we made to the Points-Cloud mode. Have you changed the display driver in 3ds Max from the default 'Nitrous' to another option under Customize > Preferences > Viewports > Choose Driver? Please try updating your graphics card driver to the latest version, as this might resolve the issue. If that doesn't fix the problem, please feel free to set the following option:
cloudPointsByObject=0
in the forestpack.ini located by default under
C:\Users\<yourUsername>\AppData\Local\Autodesk\3dsMax\2020 - 64bit\ENU\en-US\plugcfg
I hope this helps.
Best regards,