I've had issues like this too, although it was a while ago so I'm writing this from memory.
I seemed to get much better results using the Data and Text I/O addons with the fullpath option instead of the library one.
Which in itself created a whole different set of issues.
But I would be interested if other people had reliable ways of utilising these features... It has long been a dream of mine to create links between objects, and this seems to be the only path capable of doing it.
AC 24 5004 AUS
iMac OSX (10.13.6) 4.2ghz i7
8gb ram/8gb vram