Hi Stella,
Well, let’s then try the export/import first, maybe I can see something on the search instance settings that might be off. Can you please go to the export/import panel, and export all the search instances: https://i.imgur.com/QkylV27.png
Then please copy the exported text to a .txt file and upload it here. I will download and try to import them on a fresh installation.
Please let me know which search bar (name) does not work, and which is okay. I will then try to spot the differences.