Hello. What else can I check that may cause Client Performance Issue? A user is having trouble loading the items when editing Opportunity Records. The record loads fine on my end. I also logged in as him and it loads fine as well. He has good internet speed/connection We hard reload his browser(Chrome) His browser is up to date There are only 2 browser extensions What did I miss? Thanks.

In Europe we face the same issues in general here NetSuite is slow. What you can do is install netsuite perfomance and create a case.

Try installing the Application Performance Management bundle. It should give you more detail on the issue