Why is my sequence looping half way through?

MPC 2500, jjos free 3.13

Made a 4 bar loop, and used seq edit to copy bars 1-4 and add them after bar 4, making an 8 bar loop.
Added a vocal sample at the start which is 8 bars long, but the sequence counter returns to the start after 4 bars and plays from there.
I can see the whole 8 bars in grid edit so I know they are in there.

Confused!

Check where your loop point is assigned - this will be in the top right corner of the screen in JJOS.
If your sequence is looping back to the beginning after 4 bars, it's likely still set to loop after 4 bars, as you stated it started out as a 4 bar sequence which you doubled up to 8.