Two cats, still having accidents 2 years post-baby

We have two cats, one is 8 years old (bengal, breeder) and the other is 3 years old (black, rescue).

Both have been great cats with typical cat behaviors. However, I had a baby in 2023 and once we turned my office/cat room into the new nursery, we've been experiencing excessive grooming from the black cat.

Now, toddler is 2 and the excessive grooming has turned into both cats having urine accidents with the occasional poop accident.

I am at my wits end at this point, we've taken the black cat to the vet who says it could just be an adjustment period but now both cats are having accidents (we have another vet appointment for tomorrow). It's always in the same spots as well, the Bengal goes on the couch and the black cat goes in my toddler's playhouse.

The black cat has been on/tapered off gabapentin but it doesn't seem to fully help the anxiety. Now that our Bengal is also having accidents, is it possible that our toddler/less attention to them is stressing them out further?

We also have a baby gate to the litter box room but they were using that with no issue for 2 years before this happened (we wanted to make sure it worked before the baby arrived).

My life now revolves around cleaning up accidents while trying to wrangle a toddler. As much as we love the cats, we're now sacrificing our mental health to try to make them happy and now debating rehoming both of them.

Any words of wisdom or follow-up questions we should ask the vet tomorrow?