Hi,
The average request runtime there is 0.184, which is well below the 9-10 seconds response time, which probably means, that there is something else clogging/slowing the search request, even once it’s finished.
Usually the issues are firewalls or plugins that do any sort of maintenance during requests. I would probably check those first.
There is a custom ajax handler built-in to the plugin, that you should probably try turning on, to see if that makes any difference. It is used to bypass some plugin loading times, to increase the response time.