File explorer has started freezing for 20-30 seconds

My 3 month old Latitude with Win 11 Pro has developed a minor (but annoying) problem.  File Explorer has started freezing up for 20-30 seconds when first opened.  This seems worse if I have any external USB drives connected.  (I often have a 2 TB external HDD connected, as a lot music and video is archived there.)  Can anyone suggest a cure for this?