searchBox not available

I upgraded my Nextcloud from 13.0.4 to 14.0.4 on both production and test environments.
After upgrading test server to Nextcloud 15, also found there.
Operating system: Centos 7.5
Full text search version: 1.1.0
Full text search - Elasticsearch Platform version: 1.0.2
Full text search - Files: 1.1.1

After that each time I enable FullTextSearch app I see the following error in browser console:

 Uncaught Error: searchBox not available                 search.js?v=059cb2f7:61
    at Search.initialize (search.js?v=059cb2f7:61)
    at new Search (search.js?v=059cb2f7:37)
    at Search.initialize (searchprovider.js?v=059cb2f7:384)
    at new Search (searchprovider.js?v=059cb2f7:34)
    at HTMLDivElement.<anonymous> (searchprovider.js?v=059cb2f7:422)
    at Function.each (core.js?v=059cb2f7:2)
    at a.fn.init.each (core.js?v=059cb2f7:2)
    at Object.<anonymous> (core.js?v=059cb2f7:4)
    at j (core.js?v=059cb2f7:2)
    at Object.fireWith (core.js?v=059cb2f7:2)

Has any textbox been renamed in 14.0.4?

Thanks.

The stack trace points to search.js and searchprovider.js; start by reproducing the error after upgrading Nextcloud and inspect where searchBox is expected during Search.initialize. Compare the affected app and platform versions to identify the compatibility issue, then verify that enabling FullTextSearch initializes without the browser-console error.