On StackOverflow, I received today the notification Congrats, you've gained the privilege – set bounties learn more, but when I check here I realized I should have 75 of reputation for the set bounties privilege and I have only 65. In fact, the page also shows me I am currently at 86% for that privilege. Is this a bug? Have I missed something?
Someone probably upvoted one of your answers, then thought better of it and undid the upvote within the grace period.
As a result, you were briefly at 75 points, long enough to gain the privilege.
You will have lost the privilege again, but you'll regain it when you have 75 points or more again (but you'll not get another notification, IIRC).