Yes it's quite common. In general there's a term called intelligent idiot. I learn that from Nassim Taleb. My understanding is there are a lot of people look smarter than they are. I noticed a lot of the phenomenon since then.
My theory is there are some fundamental cognition defects in our sapiens' brain which was evolved from "small data" environment (compare to today's bid data environment) so the biochemical reactions inside our brain on the conclusions from Bayesian model are not much different from the reactions to the conclusions from witness. That results in many people don't differentiate beliefs(very strong but have never seen the truth) from "solid facts" which is equivalent to the topics that you know very well.
The most common places to observe intelligent idiot are the areas related to ideologies. For example there are tons of politicians showing very strong intelligent signals: articulate and organize their thoughts very well, with solid logical reasoning, while actually talking bullshit which only can be noticed by the people knowing the ground truth.
In technology areas there are less but still some. People are easily confused with strong intelligence signals with the real intelligence.
It's not black and white. Some time real smart people also make the same mistake. Give a couple of examples: Sam Harris, Bret Weinstein , I consider both very smart, rational, evidence based,scientific thinking guys according to the depth of their thinking. However I noticed they have some serious mistakes on their judgements about some matters that they don't know the ground truth. I still highly respect their intelligence but not the same as before. They are not intelligent idiots but just made small mistakes. Meanwhile I think I might have the same problems that I don't know since they are smarter than me and still make mistakes.
Here in HN with a high density of smart people, there are tons of chances to observe intelligent idiots. Just check those non-technology related hot topics.