Issues with Large Files

[Budge]

I have recently had trouble playing radio 3 operas on my Linn devices. 
These files used to play although there were problems.  They play well 
on my RPi3 with IQaudIO DAC+ amd upmpdcli gapless player software. 
(Totally brilliant setup which enables me to use excellent power 
amplifiers which would otherwise be redundant.)

I asked Linn for help which they are working on and received this reply:-

As a workaround for now, you could convert the file to a different 
format. I've checked that it plays after converting to either FLAC or 
ALAC using dbpoweramp.

You might even find that just re-writing it as AAC fixes things - the 
problems are caused by the file being split into an enormous number of 
tiny chunks (over 400,000 audio blocks for a 9,200 second track); any 
encoder which reduced this would allow the file to play.

Please could somebody tell me if this is correct and what should be 
there or have I done something wrong with my gip installation.
Budge