Group migration field assignement issue

Hello,

Issue 1 :
After migration from jomsocial some of my groups took event fields. (pic01.jpg)

Issue 2 :
Some field doesn't match well (pic02.jpg)
Her you'll see that the Group Title is unset whereas the Group Type is displayed as group Title in group view (pic03.jp).

I tried to look at the database but did not understand how it works (clusters...)

I've searched the forum but didn't find any similar issue.

An idea ?