NetSuite support has logged a defect about this issue and are looking into it. Seems that there is something going on.

Could you please share that defect number so we can reference it with support?

Defect is 785388 : Performance > Multiple Records > UI Performance > Cannot toggle over tabs and subtabs FYI -- @Joe Masek advised having users manually update Chrome to the latest version. I did this with several users yesterday and that seemed to resolve the issues. As of this morning, I haven't heard anything from NetSuite about the defect. Considering how much of a problem this was for my sales team, this would have been a huge problem not getting any resolution 24 hours out.

Thank you