I just updated my free version to V5.51.6939 and was analyzing how much junk was in certain applications.
I right clicked on Google Chrome and selected Analyze, which it did, but then the programme continued to analyze everything, possibly cleaning at the same time because when I tried to repeat the process, there was nothing to clean. I didn't press either of the large "Analyze" or "Run Cleaner" buttons on the main page beforehand.
Also, there is usually a warning pop up box prior to cleaning, but nothing appeared.
As far as settings go, I never enable smart cleaning, and I confirmed it's not running. Auto run at startup is also disabled.
I'm using a Laptop - Lenovo G50-70
Windows 10 V1803 build 17134.471