Are you sure?

Doesn't Keil have a generic 'CALL' pseudo-instruction that the assembler may ttanslate to either LCALL or ACALL as it sees fit?

If it does, then it might be using ACALL when the function is "local", and LCALL when it is EXTERN...?


That could mean:

There is a fault in your target hardware;

There is a hardware-dependent fault in your code (eg, a timing issue), which happens not to manifest in he simulator;

Both of the above