are the trouble computers having an issue with other deployments or just this one? I have had a similar problem in the past and had to delete and then re-add the asset to fix it.
you can add "sophos endpoint agent" or whatever the installed AV name is to the antivirus list under software>antivirus settings to make it show as installed, but you loose the ability for it to show if it is out of date. that said, they seem to be a...
It should still show up as installed software right? maybe pull a report for all computers that have that software? no idea how to make it show as AV protected though. having a similar issue with sophos myself.
Is it an MSI or EXE? If it isn't an MSI installer you will likely have to check your documentation or contact the vendor and ask what if any switches they have for a silent install.
I can't even get Sophos Central antivirus to reliably show as installed and up to date, and it is the only Sophos product we run on most machines. are you using it?