I was given seven problems to submit via an online coding service called remoteinterview.io. Three problems included HackerRank style challenges. I was able to solve everything within an hour (though, it take me closer to two hours to code the edge cases for the third one), and the time limit was eight hours. Everything was green; all tests cases were solved, minus any hidden cases I didn't know about. Next day, auto rejection.
How common is this? It's not my first time dealing with this. I find the interview process such bull crap, at the moment.
Note: I did document my entire code, which included my plan of action before writing anything and any necessary comments.
I got turned down by MIT. Yeah, it sucks but anger will hardly help.
And there are always upsides. In my case I went to state U on full-ride and saved myself $170k in tuition. In your case, you avoided being hired by a less-than-competent company.