Too Many Outstanding Queries

I am having major issues with a site that has Estatik Installed. I have the automatic imports set up with a few different requests. Each of them are triggered once per hour and should only pull in 5 listings each time. This works for a short period of time, and then eventually it starts saying “too many outstanding queries” and this prevents new listings from being added and sold/cancelled listings from being removed from the site. I feel like what I have set up is pretty conservative in terms of how many listings are being requested, but seems to always have this issue. Any thoughts on how i can ensure that listings are always being added to the site and old listings are always removed?