I created an event, set the invitees, and set reminders.
In the past, both parents of this family received the reminders.
Yesterday, one parent, #1, of this family received the reminder email, the other parent, #2, did not. Both are invitees.
I went into #2 parent account and updated her parent connection, her den admin role, and her Assistant Webelos Den Leader position. I deleted a duplicate AWDL position created by Akela sync.
Today, again, #1 parent received the event reminder, and #2 did not.
I created a Scoutbook Support ticket, SSD-72739
edit - The reminder is not in her spam/junk folder.