Shared Calendars Syncing One Way (A ➜ B but not B ➜ A)

Hi Everyone,

I’ll start by saying I’m an Android user, but I’m helping someone who uses iPads and is running into the following issue:

Events created in Calendar A sync correctly to Calendar B,

but events from Calendar B do not appear on Calendar A.

Setup:

• Two users, each using the Apple Calendar app.
• Both have shared their respective iCloud calendars with each other.

I’ve reviewed the obvious settings, and both sharing permissions seem to be configured properly.

My question:

Is there a common or easily overlooked setting that could prevent iCloud calendar syncing from working in both directions?

Thanks so much for any insight!