Bellingham has been unreliable so far and his form so far has been questionable. Bellingham has been very different this season and he has really lost his best form, so I don't completely agree with your opinion. On the other hand, Mbappe is still trying to improve his performance on Real Madrid's front line and I understand that considering this is his first season at Real Madrid, he is still adapting even though many fans have high expectations of him.
Actually, Jude's performance is still quite good, it's just that when talking about a performance that does prioritize goals as a statistic, of course this is reduced but in the end it is also understandable because the position Jude is in for this season is different from before.
Last season Jude was always placed behind the striker with the 4-3-1-2 scheme being the mainstay but when there is Mbappe in the Madrid squad then it is quite tactical position and the 4-3-1-2 formation may be forgotten because Ancelotti prefers a 4-4-2 or 4-3-3 formation which makes Jude's position shifted as an attacking midfielder just like he had at Dortmund.
In the end, the change in position has reduced his goal productivity but that does not mean that his performance on the pitch has decreased because in the end in his current position he is still playing very well.