The field on the search form appears to be render cached.
Steps to reproduce
On a clean site, configure gcs. Place the gcs block in the content region, and give permission for anon to use the search
In a browser (browser 1) as an anonymous user, navigate to a page with the gcs block, but do not submit.
In a separate browser (browser 2), log in as an administrator and clear the caches
In browser 1, perform multiple searches. The search results should always be correct, but the value in the input should be stale
Proposed resolution
This module uses Gitlab CI for automated testing of proposed code changes. To contribute code changes, create a merge request. Patch files will not trigger automated testing and are not sufficient for review.