We ran into an issue where several applications (Wireshark, Java, etc.) ran into errors when attempting to update an existing AppStack. We recently rebuilt our provisioning machine with a clean install of Win10 1909. The errors varied but frequently came back with an error code of 110 or a message that it "can't access resource".
I found some other posts here and elsewhere on the Googles that an entry for msiexec.exe in the AppVol hookinjectionwhitelist fixed some similar issues in previous versions (want to say AppVol 2.14) but it seems to still be relevant. The provisioning machine in our test environment already had this entry so we're thinking that clean installs versus upgrades caused us to have slightly different configurations.
Just wanted to post here in case anyone runs into the same issue.