According to Windows 10 Pro Fall Creators Update Task Manager it was running at 0.47 GHz and it wouldn't go any higher. The laptop was completely cool as I just turned it on. BTW I am running a power profile set to TDP 35W.
Even opening a folder would take a few seconds. Windows sounds were very laggy and choppy. I asked Windows to shut down the laptop and after the screen went dark. It took over a minute to turn off all lights. Fan is usually not running and I am using SSD so there aren't any other noises.
After I rebooted Task Manager agrees with CPU-Z - the CPU is idling at around 0.89GHz and everything is running smoothly as usually. CPU is going over 1GHz when loaded.
Any ideas what might be causing the throttling?