O'Neill says Sessegnon is now feeling much more settled at Sunderland, having initially struggled to adjust to English life following his move from Paris St Germain 18 months ago.
"He texts in perfect English now! He understands. There is an element of that (whether his family are happy) but there's only so much you can do," said O'Neill.
"If some families can't settle in areas or countries then you have to take it into consideration.
"That was an issue and I just hope that issue disappears again this year - I don't want that to rear its head again."