I'm not sure I'd regard a change from Nihon Goshin Aikido to Aikikai as a mere change in style. What most of us regard as different styles of aikido all trace their origin back to Morihei Ueshiba.
Nihon Goshin Aikido however doesn't, so I think it would be more accurate to describe that as a similar, but separate, martial art from (what most of us mean by) Aikido - which, confusingly, just happens to have the same name.
Not that necessarily has any bearing on your situation though, just saying it because nobody else has so far.