Restore_cache job has started failing but always succeeds on re-run

A few days ago our builds started failing when attempting to restore a cache. The error message is:

Found a cache from build [build number] at [cache]
Cached paths: [file paths]

Downloading cache archive...
Validating cache...

error validating cache: EOF

When rerunning the build job from failed, the cache job always succeeds afterward - as if it can now correctly determine the cache exists and read from it.

Is anyone else experiencing this issue?