If events have disappeared from your Shared Family Calendar in the monthly view, follow these steps to troubleshoot and potentially resolve the issue:

Check Calendar Visibility Settings

1. Open the Calendar app on your iPhone.
2. At the bottom of the screen, tap on "Calendars" to view all available calendars.
3. Ensure that the checkbox next to your Shared Family Calendar is checked. If it's unchecked, tap it to enable visibility.

Restart Your Device

1. Press and hold the side button and either volume button until the power off slider appears.
2. Slide to power off your iPhone.
3. After the device is completely off, press and hold the side button again until the Apple logo appears.

Ensure Correct Account Sync Settings

1. Go to "Settings" on your iPhone.
2. Scroll down and select "Calendar."
3. Tap on "Accounts" and ensure that your family account is listed and set up correctly.
4. If it's not there, tap "Add Account" and follow the prompts to add it.

Check Family Sharing Settings

1. Open "Settings" and tap your name (Apple ID) at the top.
2. Tap on "Family Sharing."
3. Ensure that the family members' accounts are correctly set up. If someone is missing or has left the family group, re-invite them.

Update Your iPhone

1. Go to "Settings."
2. Tap on "General," then "Software Update."
3. If an update is available, download and install it. This can resolve any bugs affecting calendar synchronization.

Restore Calendars and Events

1. Visit iCloud.com and log in with your Apple ID.
2. Go to the Calendar application on iCloud.
3. Check if your Shared Family Calendar appears there; if it’s visible, it might need to be re-added to your iPhone after restoring visibility.

Sign Out and Back Into Your Apple ID

1. Open "Settings" and tap your name to access your Apple ID settings.
2. Scroll to the bottom and select "Sign Out."
3. After signing out, restart your device and sign back in to your Apple ID.

If these steps do not resolve the issue, you may want to check forums or support pages for potential ongoing issues with Apple’s services which could affect your calendar, as mentioned in community discussions (Apple Community - [learn more]) or review iCloud calendar restoration steps (Apple Support - [learn more]). These resources might provide further assistance or updates on common issues related to Shared Family Calendar events disappearing.