The JMP date/time values are based upon the number of seconds from the date midnight, January 1, 1904. The applying a format on a date/time column, does not change the underlying numerical value. Below I have taken the graph where you have not restricted the X axis range, and just changed the format being displayed and overlapped it with the original axis.
The axis shows a range that covers only the day of December 31, 1899. On your second graph, somehow the axis range has been set across a date range starting beyond any date/time in you data, December 31, 1899 10:44:14 AM to January 1, 1904 12:00:00.
My guess is that this is happening by setting the Minimum and Maximum with just the time part of the date/time column. I suggest that you change your format to a date/time format, set the range, and then change the format to your desired time only format.
Jim