Posting here opens a support ticket. To troubleshoot your machine, support will ask you to print the Gift of Good Measure on medium draftboard, and post pictures of the results. If it’s determined to not be operating correctly, it can be sent in for repairs.
A properly functioning machine with clean optics will cut Proofgrade material cleanly. I’ve had mine for over two years and it still performs flawlessly - although I’m sure my day will come at some point, the tube has a finite lifespan.
If you want to experiment with non-proofgrade settings to find something that works with your machine, there are dozens of threads on how to approach this, including: