Could you please post a screenshot of the graduated filter settings so that we can try reproducing this issue.
Thank for your answer.
Attached the screenshot which correction -2IL on the sky.
Sorry I cannot send you the screenshot.
I will try to morrow.
Do you have pull the graduated filter from the top or the bottom of the picture.
For me it seems that you have pull from the bottom.
Delete the filter, create a new one and pull from the top.
I had pull the graduated filter from le middle of the sky like always.
I have tried from the top of the picture and this is OK.
After I have tried from the middle of the sky and this is OK too.
I think there was a problem with the software LR 6.
Thanks a lot for your help.