Hi @JimBimm sorry that the QTS 5.2.6.3195 has a known issue that cause the increase of CPU usage, you can refer to this post
Qfinder detects it under its normal IP address, but I cannot login via Browser
Rolling back to QTS 5.2.5 should can resolve the CPU problem. But you mentioned that you can not login it via browser, you may need to open a support ticket on the Customer Service website and use Team Viewer to allow the support team to remotely downgrade your NAS.