Dso activated issue

Hi experts,

I face a very troublesome issue when activate DSO: I add two new fields(Charicteristc) to a dso that have history data in it, when I  load data into it, the new added fields value is null but they are not null when I check in new table, how can it change to null after activating data ?

PS:this issue happen on product system, there is no issue on q system.

Hope some one can help me for this,thank you very much !

Best regards

Vincent