I'm curious what version of App Volumes, Horizon, and guest OS are you using? I've had lots of problems with putting Autodesk apps in appstacks with version 2.18. I finally just installed all versions of Autodesk apps in the instant-clone pool parent VM, but even then I had to revert the App Volumes agent in the desktop pool back to version 2.16 in order to avoid errors when a user opens Revit and AutoCAD at the same time. I haven't started testing it yet, but I'm hoping App Volumes 4 will provide some relief. I'm not going to hold my breath, though....
Yes, we are 2.18. I believe I was having the same issue in 2.16 as well. Are you using the Autodesk Desktop Connector at all?