Why is my file is marked as infected but no engine detected it?

See the following results as an example:

https://metadefender.opswat.com/results/file/bzE5MDMwNUh5bGVZa0FCaThFQkpXZUYxQUJpVTQ/regular/overview

This is an archive file (APK) and one of the files inside the archive have been marked as infected. When scanning the archive as a file, no engines detected a threat, but because one (or more) of the individual files extracted from the archive were marked as infected, the whole archive is marked as infected.