Had a similar split with two cats. The slower one caught up eventually on her own timeline, no special intervention needed in the end.
We moved with a dog and two cats, and the difference in how each of them handled it has been fascinating and occasionally stressful in equal measure. The dog was anxious on travel day but settled almost immediately once we arrived. One cat adapted within a week. The other cat is still, three weeks in, hiding under furniture and only eating at night when she thinks nobody's watching.
I wasn't prepared for how differently three animals from the same household could react to the same move, and I'm not sure whether to just wait it out with the anxious cat or actively try something.
Anyone else moved with multiple pets and seen this kind of split reaction? Did the slower one eventually catch up on their own timeline, or did you find something that actually helped speed it along without stressing her out further?