This issue could be due to hidden processes, outdated drivers, high system temperatures, or PSU issues. First, check Task Manager for unexpected high usage processes. Next, ensure your AMD drivers are up-to-date. Monitor your system's temperature with a tool like HWMonitor. If these don't resolve your problem, consider the possibility of PSU issues or software conflicts. A clean Windows install might help, as it did before. If all else fails, consult a professional. Remember to back up your data before performing any significant troubleshooting steps.