Are the Mayans Long Count bugged?

I really like the Mayans for their style of play but the Long Count calender should be active on turns 62 72 86 101 117 133 152 183 234 after Theology is researched. Can you explain why I didn't get a great person on turn 86? I researched Theology on turn 85 . Thanks.

You need to finish researching Theology 2 turns before the new bakt'un starts. So, you need to finish Theology by turn turn 84 for the turn 86 GP.

A great person appears every ~396 years. The great person didn't appear because 396 didn't pass at that turn after the last great person appearance.