It may very well be that neither is suited for indoor use. Plants that grow freely or easily outdoors in your climate are very unlikely to do well under indoor conditions.

Thank you for your response. They were both super happy and growing well for months after I got them so thats not the case.

Unfortunately, that IS the case. Anything can be grown indoors for a limited amount of time but that does not mean it will continue to thrive under similar conditions going forward. The simple fact is these are NOT houseplants!!!!

I know these are not houseplants. But I have friends and know other people who has them inside their homes for several years now. As long as they have been grown for indoor use and get enough sun they will be fine. But thank you for your opinion. I have contacted the nursery and hope to get some expert help on the matter.

Maybe overwatered and lack of air to the roots?

And jacarandas grow into pretty large trees. I'm not familiar with the other, unless it has a common name?

And when you repotted, were you careful to keep the soil at the same level on the trunks?

Perhaps! I did not pot them very low, pretty much the same as before. Just a larger pot. The bucida is also called a Shady lady or a black olive tree :)

You didn't say if you did but repotting trees when in full leaf can cause transplant shock, with symptoms similar to what you show.

I definitely did.. Do you know if they would be able to recover?