Hi,
Ah. There is an issue with many DMMs when on DC which is varying. I see where you found that out with yours.
The root cause of that issue lies within the Analog to Digital chip inside the meter, so it isn't a make or model specific issue. It is a 'low cost' meter issue.
This is why I always use Fluke brand meters. Multi-hundred dollars each ones. They don't have such issues. Nothing worse than to be shooting trouble that is a figment of your instrument's imagination.
Plus, Fluke meters have this nifty analog bar graph along the bottom of the display. So you can see the variations *and* also have a steady digital reading at the same time.
Yeah. I know. I sound like an ad for Fluke. Well, all I can say is: If it works well, it's a Fluke!!
Next up, a pitch for Tektronix and Hewlett Packard (aka Agilent and now Keysight. I wish they would stop changing their name).....
Stan