For some reason, the animation played by a character is offset by a noticeable amount. You can see the original compared to what it looks like on the character. Is there a way to fix the misplacement? Reference gifs below:
Got a better gif with the moon animator if that helps at all. Here, you could see that the hands are crossed with the character rig while the original plays fine.
Looks to me like the custom model is considerably thinner in the first place. Also, the arms do not appear to be starting from the same place. the dummy is in an A pose and the custom one is almost straight down by the look of it.
As the animation moves the joints relative to their starting position/orientation there is not much getting around this.
Potentially you could try playing with the rig but that will affect how all other animations play on it too.
Other than that, I can’t really see an easy option to fix this, scripting a dynamic animation that accounts for the size and shape of the character is the only fix I can think of that would give the results you desire, where the hands both hold the phone nicely.