Rise edge not working

I have an interesting problem.
Working with Step 7.
I'm trying to set a memory with some conditions and one of them is the rising edge of a signal at an entrance. The thing is, it doesn't work with the rising edge function and without it, with just the input set to true, it does work.
I realy can't find a logical explanation for that.

Here is the code that works:
A #Pump_OK
A #Auto
A #Start
S #Full
A #Sensor
R #Full
A #Full
= #Motor_forwards

And this don't work:
A #Pump_OK
A #Auto
A(
A #Start
FP #startFlag
)
S #Full
A #Sensor
R #Full
A #Full
= #Motor_forwards

I am debugging with a real CLP, no simulator.

I need the rising edge because the start signal will not be constant.

Tanks.

#startFlag

What type of variable is this?

It won't work as an edge memory if it's a TEMP or is used elsewhere.

The variable is STAT in an FB.
I analyse in two networks the rising edge of Start, but the flags are different startFlag and startFlag2.

Your code works fine in the simulator.

Was #Sensor true while you were testing by any chance?

It did work.
Went to lunch and shut everything down.

Came back, turned it on, reloaded ant it works.
Maybe trash in the memory. Who knows.
Thanks anyway for the quick reply.

Can I close anyhow this useless thread?