It appears that the report engine does not respect a sort on a yes/no attribute, at least when the report is placed as a sub report. Here is a vide to demonstrate the issue:
https://youtu.be/ZXAtTWRCpz0
Sorting error in report engine
Sorting error in report engine
V8.8
MySQL, AWS EC2, S3
PDFtk Toolkit
MySQL, AWS EC2, S3
PDFtk Toolkit