Merriam Webster informs:
If you treat a convention with disdain you are flouting it. If you make an ostentatious display of something then you are flaunting it. So why is this a problem? Mainly because people seem to have the habit of using flaunt to mean flout.
It’s part of the problem; the other problem is that some people are too lazy to look up these words in the dictionary to understand the elementary distinction.