Assuming all the ones labeled as the same Chapter do belong to the same issue, then it goes as follows:
October 1996 is already labeled as such.
Chapter 7 is November 1996
Chapter 8 is December 1996
Chapter 9 is January 1997
Chapter 10 is February 1997
Chapter 12 is April 1997
Chapter 13 is May 1997
July 1997 is already labeled as such, which by the numbering means that pic labeled Next Gate 25 would belong to it too
Chapter 16 is August 1997
September 1997 already labeled like so, corresponding to Next Gate 27
Chapter 18 is October 1997
In any case, the covers should be correct at least. Doesn't look that Next Gate skipped issues, in any case.