Haltech Nexus R5 engine protection active bit with no error code??

Hi

Just thought if someone has come across this. I'm trying to tune my new engine build but I keep getting an engine protection limit, which is level 1 and set to 5500 rpm.

The engine limit function is 19, which is engine protection, but no error codes are displayed, and in the log, the engine limit function cause is 1378. Does anyone have the legend for the causes??

I have checked all my sensor settings, and none are causing the cutout. Every sensor is working under the thresholds I've set.

Thanks in advance