QC problems with the Sysmex XW-100, Suggestions please!

I was wondering if anyone else has had issues with their CLIA waived Sysmex XW-100 having QC invalid errors every two weeks? Every other Saturday night/ early Sunday morning when staff try to run requested QC it will give the error code 2609 (0,0) QC invalid. The error will not clear by turning off the analyzer and only running new QC vials will solve the error. Sysmex Technical Solutions say there is nothing wrong on their part and my IT people say there is nothing wrong on their part either. We got a new XW-100 analyzer and it has the same problems. Help me! Any suggestions would be super helpful.