Okay, I’ve tested the same files on the second drive and can confirm that the issue follows the files.
More so, the issue occurs at the exact same point in each file every time, which suggests that there is a problem either in the file itself or a problem with the way the player reads or handles certain data.
While it’s not a pressing issue, as I’m rarely skipping my way through movies, I’m keen to hear if anyone else has the same problem and what/where I can look for a resolution.