Precision 7560 USB issues

Have purchased multiple (12) Precision 7560 laptops and am starting to see users with intermittent USB device issues.  The primary issue is USB keyboards and mice are freezing (not typing or mouse movement).  Have tried both Bluetooth and wired keyboard and mice with the same issue.  Have done a Mr. Google but no similar issues have come up.  All software up to date including drivers and Windows 10.  Have tried with docks and without all with the same issue.   Have run diagnostics with no issues.   Next is a warranty call as I've already spent way too much time fault finding.  Anyone else had an issue?