This could potentially be due to JSON Max results i.e. json.maximumresults, [1] assuming the query is fine. When this limit is exceeded the rendering will be collapsed. [1] Security Checklist

You can use JCR Query Cheat Sheet [1] to build your query. It might be easier to build a SQL/SQL2 query then you can generate the xpath query from the SQL query in CRX/DE[1] https://wiki.magnolia-cms.com/display/WIKI/JCR+Query+Cheat+Sheet

Ref: The query read or traversed more than 100000 nodes. To avoid affecting other tasks, processing was stopped.This seems to be an issue with many nodes to traverse. Check the log to find the problematic query and create an index. you can use Oak Index Definition Generator: Oak Utilities : Index De...