A bit of follow up.
I went ahead and installed it on the base Image. It works fine there.
I also was able to use it without any errors while it was being provisioned on the appprov machine. As in I updated the appstack, while it was provisioning opened VS2019, signed in and grabed the license without issues. However when I captured it again and attached it to a pool it was still giving the original error.
That leads me to believe its something related to appvolumes but I am not sure what right now. We previously had VS2017 working on a appvol 2.15 appstack and windows 1803.