Zeppelin 0.9.0 search box does not work after upgrading from version 0.8.1

Hello everyone. I had three zeppelin servers on three different machines. After upgrading them from zeppelin 0.8.1 to version 0.9.0 the search box which used to search the entire notebook contents does not work anymore on none of them. I have upgraded all my notebooks to newer notebooks' format for zeppelin 0.9.0. I checked the configurations in the previous zeppelin installation and found nothing useful. After that I checked the Zeppelin REST API documentation  [here|https://zeppelin.apache.org/docs/0.9.0/usage/rest_api/notebook.html] I tested the API for most of query types and it works perfectly. The only problem is when using full text search. I use the following format:

http://[zeppelin-server]:[zeppelin-port]/api/notebook/search?q=[query]

For all queries it returns nothing with status of 200. I appreciate if you help me with this problem.