Hi Katy:

The best place to start troubleshooting query performance like this is the query profiler. You'll reset statistics, perform the add or edit task, then recheck the stats to see whether there is something unexpected happening or taking longer than expected. This topic has more detail and some troubleshooting leads.
https://www.labkey.org/Documentation/wiki-page.view?name=queryperf

I'll move this question to your premium support portal where we can better provide custom assistance.

--Molly