As any search for “Quora” on Upwork will show, plenty of people are being paid to write answers on Quora, without being state agents. Quora has strictures against spam; it does not have strictures that I know of against propaganda.
From my outside perspective, I keep thinking Quora is one bad news story away from being in a world of hurt. But the bad news story hasn’t happened since 2014. And at least this year they’ve hired a lawyer.
Spam is not the right category for suspected professional propaganda or astroturf, but it’s close enough to serve for reporting, and it’s better than mere “factually inaccurate”. Do give an argument for your suspicion if you make a report, though.