This is because the end byte checking code in this app, was not updated when the firmware changed to send various end byte values, depending on board mode.
https://docs.openbci.com/Cyton/CytonDataFormat/#binary-format
The following table is sorted by Stop Byte. Drivers should use the Stop Byte to determine how to parse the 6 AUX bytes.
This would be an easy fix. User Professor James Taylor comments here:
https://openbci.com/forum/index.php?p=/discussion/comment/17802/#Comment_17802