Lastduration vs duration vlaue sin the object model

[Tinchus]

Hello. Im wanting to read the total print time of a print once the print has finished or at the time it was cancelled. Both situation are related to a M= code, wich triggers the execution of stop.g.
So from that file I want to read the value of the print time of the finished/cancelled job.
So far job.duration seems to acumulate the printing time of the ongoing print BUT looks like it is inmediatly put into a "null" value if a print finishes or if it is cancelled, making any attempt of using that value not possible because if you try to use it on the stop.g you get an error saying that "a numeric value was expected", it is logical since I can see that a NULL value is there

But a similar problem arises if I try to use job.lastDuration. This object seems to accumulate the printing time of a finished/cancelled job but I got the same error when trying to use from inside stop.g. It looks like its value is writen on that object sometime after M0 is executed so stop.g looks like still doesnt have access to its numerical value

Any comments or may be there is another object that I can query in order to get the printing time from stop.g or ideas on how can I access that information using configuration and not from the end gcode (I want to control all from the configuration side and not using any gcode coming from the slicer)

I have a duet3, SBC mode with 3.4.6 firmware