changing original duration in resource tab won't work

hi all,

I kinda have a problem linking original duration from the STATUS tab and the one in the RESOURCES tab in P6.2.1.

let's take a random task :

OD 4

UPT 200%

BQ 8

till now it's normal, but when I change the OD in the RESOURCE tab (it's not present by default but we can add it) because right now it's easier to assign a *new* duration in here, the BQ is updated but the OD in the STATUS tab isn't.

and it doesn't work in reverse either, when I change the OD in the STATUS (or in the column I just added), it doesn't update in the RESOURCE tab, and it doesn't even recalculate BQ.

the problem is, I discovered this problem after having typed lots of new durations so I'm kinda stuck !

FYI, every task is set to "Fixed duration & units/time" (we need that), and I'd like to think I tried every possible combination in the options tabs everywhere.

am I missing something ?