If a user is still receiving a SearchEngineRequestFailedException after a system reindex and patching, there could be several reasons for this.
Firstly, the issue may not have been related to the index or patching, but rather a problem with the user's search query or the way they are interacting with the system.
Alternatively, it could be that the reindex and patching process did not fully resolve the underlying issue, and further investigation or troubleshooting is necessary.
It's also possible that there are other technical or environmental factors at play that are causing the exception to continue occurring. In any case, it may be necessary to consult with technical support or seek out additional resources to diagnose and resolve the issue.