PokerTracker

I have noticed that often the last hand before I get moved to a new table doesnt register in PT4. Is this due to PT4? Or PokerStars?

I haven't seen any other reports of this and it's not a known issue. PokerStars saves your hand histories to a text file on your computer. You can open, read and search these files with a text editor such as Notepad or Notepad++ so you can check to see if the last hand before the table move was written to the hand history file. By default PokerTracker 4 archives your auto-imported files to your 'Processed' folder which you can access via the 'File -> Open User Data Folder' option:

Guide: Processed Files

If PokerStars hasn't written the hand history or if it isn't complete then PokerTracker 4 wouldn't be able to import it. If you have missing/incomplete hand histories you can request them again from the PokerStars client or from PokerStars support. If the last hand before the table move exists in the hand history file or if you are not sure then please attach the relevant hand history file to a Support Ticket with as much detail as you can remember about the hand.

I will keep an eye out. It happens daily almost. I play 4-8 tables so I dont always notice it. But often when I do its if I get moved right after a hand was played.

If the table window is closing too quickly then the hand history might not be getting saved. Did you try my suggestion and request the hands for those tournaments from PokerStars? If you ask for the hands from those tournaments and import those into PokerTracker 4 using 'Play Poker -> Get Hands From Disk' and PokerTracker 4 reports that new hands are imported then that would indicate the hands were not in the files that PokerStars saved while you were playing.