Hi, again @hagen.deloss!
Thanks for the feedback. I feel that I need to clarify some things since you mentioned Substance Painter. I hope this will help avoid confusion. The substance 2 plugin is a node that reads Substance Designer materials (aka *.sbsar files) and turns them into "maps" that the 3dsmax material editor can use in a very convenient way as opposed to exporting a bunch of bitmap files. If you're not familiar with it take a look here (the plugin is free):
https://www.allegorithmic.com/integrations/substance-in-3ds-max
An older version of the plugin is also included with 3dsmax, but the plugin wasn't maintained by Autodesk, and can't read new versions of Substance materials, so Allegorithmic took back the responsibility and developed the Substance2 plugin.
You can find some free materials to test here:
https://share.allegorithmic.com/libraries?by_category_type_id=4
Materials can also be created by the user in substance designer, or you can download from Substance Source (a subscription service from Allegorithmic).
Substance Painter is a different application, also from Allegorithmic, but isn't a part of the issue, since Substance Painter outputs regular textures files like png, jpg, TGA, etc. It's easy to get confused about the different Substance programs from Allegorithmic if you're not familiar with it
And regarding the issue I have, it seems to be an issue (bug) in 3dsmax, according to Allegorithmic: https://forum.allegorithmic.com/index.php?topic=26063.new#new
Allegoritmic's staff say: "Yes, the second issue is due to Max not clearing state. They are aware of it, as it is in their developer documentation. I doubt they will ever fix it."
I hope Autodesk will prioritize it if it's possible to fix or work with Allegorithmic to find a solution to work around the issue.