This problem was a widespread bug back in February, which Google addressed and fixed.
Barry explains my current issue in this article from last December, because he himself saw these problems - [
seroundtable.com...]
In the last 2 days, I've noticed several of our articles being tagged with this "non mobile friendly" label. Not a large amount of articles... probably about 1-2 articles per day, out of 30-40 posted articles per day.
2 of the mislabeled articles had the "non mobile friendly" message go away without any intervention on my end.
The few articles in question, I checked them on Google's Mobile Friendly test and fetched them as Google, and everything seems perfect.
Not sure what's going on with the mislabeling issues. Could be a bug, maybe one of my banner ads acting up with the Google Bot. Hard to tell at the moment.