In the blog post at https://blogs.nasa.gov/sunspot/, Voyager engineers point out the difficulty in diagnosing problems and crafting solutions for a spacecraft with a signal round-trip-time of almost 2 days and hardware/software developed over 46 years ago using technology long since obsolete.
"Finding solutions to challenges the probes encounter often entails consulting original, decades-old documents written by engineers who didn’t anticipate the issues that are arising today."