Thanks, @EricM_Inovelli. I updated my device handler and switch out the child, per @Eric_Inovelli recommendations. That didn’t seem to fix my issues with the newer Smartthings app. However, I followed the guidance here, by excluding and removing the device and then adding it back, and the new app found the NZW97 and appears to have used (kept) all of the new device handlers I added.
I’m back in business! Thanks.