Thanks for your reply.
I selected the track that cuts off early, pressed CMD+I the stop time was fine matched the duration of the track.
I also selected a different start and stop time to see if iTunes behaved differently, but no the problem persists.
All my mp3 music files are stored locally, and so I had a run into disk utility to check health of my internal SSD drive mounted on my MacBook Pro, the health check was successful and apparently there are any issues in my drive.
Last check that I did,
I just went to my iTunes music folder, found the track that stops early and just pressed the space bar to listen to the track and the finder played a preview of the track with no issues at all until the end.
I don't really have a clue why iTunes behaves like this? It does this with some mp3 files, fortunately not all of them, but is getting more frequent with new mp3 files imported to my iTunes library.
Many Thanks
Rui