Answer:
This is a known issue with the software and is caused if the project is compiled with PSoC Designer 4.3 or more recent. This problem is caused because the BOOT.TPL file has been modified from 4.2 to 4.3. What prevents this specific project from working is a long jump interrupt call that doesn't get copied over when the project is updated by PSoC Designer 4.3.
To fix this, please add "ljmp Sleep_ISR" to line 131 of BOOT.ASM, or overwrite the existing BOOT.ASM with the attached one.