A message from JMP creator John Sall
There is a in-depth description of the problem in an older version of the JMP DOE Guide
https://www.jmp.com/support/downloads/pdf/jmp_doe_guide.pdf . The popcorn example is used in the introduction chapter and documented including the analysis via GLM beginning with page 15.
Hope that helps.
Tried it without success. Are you using the current V12 example for popcorn.jmp? The factors and response are different from that used in an earlier version that you recommended..