[HSY] Prom disappears from Calendar

I've never had a problem with the Prom. It's always shown up in the Calendar and the Prom options have always been available. Now... There's nothing. Nothing on the Calendar and no invite options.

Tested with a copy of my regular game with Mods removed. 

Update: Tested with a vanilla game I was using for something else. Hadn't played with any children or teens. Added a Household with a teen. 

First day the Prom appeared on the Calendar.

All the Prom options were available and my Teen was able to successfully attend the Prom.

After attending the Prom it disappeared from the Calendar. 

I tried adding a Teen to a second Household, but as noted by AxelRogat​ the Prom event seems be available for one week and then it's gone.

EA_Cade​ et al. A copy of the Save I tested this with can be found here:

 https://drive.google.com/file/d/1ITAz3VBO7AZKd9MqfmCsGPql4xXw6Ajg/view?usp=share_link