If you can obtain the files, I can do a comparison, but these would all be signature based.
Signatures are what 'find' the malware / ransomware etc.
The signatures aren't going to change version by version from 6.0.8 to 6.2, unless the malware itself is changed (or there was an issue with the signature in the first place, to which we push updated signatures out).
I am not disbelieving you, But without knowing the exact file, the exact signature- this is a lot of 'he said', 'she said'.
There was a few issues with some signatures about a week ago, in regards to detecting certain files, as malicious when they weren't, which were corrected.
I would need the malware file(s), to conduct any test to see the following:
1) IF something has changed between versions (signature versions or software versions)
2) what signature(s) are being detected
Though, nothing should of changed (other than the signatures possibly and I don't know that without the sample malware file(s)).