Any issue with passage or particulates impeding flow and operation would be limited to the valve body. If your fluid ops don't bring joy, then drain and strain and save that spendy fluid, pop the pan back off, grab ya a pic/diagram that shows the specific screws that hold the valve body in place, and pop off that valve body. Take to bench, disassemble one section at a time, clean and reassy in like fashion (get gaskets)

Amazing how much little goopy stuff you will find hanging out in nooks and crannies. Most of a Saturday is more than enough time to do a thorough clean and inspect.