Starting with playing a sound triggered using Find My, your iPad will only respond when it receives the command to do so - and this can only occur if your iPad has (a) an established internet connection and (b) is able to communicate with Apple's servers. Your description might suggest that your iPad doesn't have a reliable connection - and this can be influenced by a number of external factors of which you may have little control.
A restart of your WiFi/Internet router may be beneficial. To cleanly restart your router, completely disconnect its power - and wait for at least 30-seconds before reconnecting and allowing the router to restart. Restart may take several minutes.
If your iPad is not operating as expected, try a forced-restart - as this will often clear an isolated software issue:
Force restart iPad (models with Face ID or with Touch ID in the top button)
If your iPad doesn’t have the Home button, do the following:
- Press and quickly release the volume button nearest to the top button.
- Press and quickly release the volume button farthest from the top button.
- Press and hold the top button.
- When the Apple logo appears, release the top button.
If the problem persists after performing the restart, it may be necessary to reset your iPad settings. While this reset will not cause any loss of data, as a precaution, it is always wise to ensure that you have a current iCloud or iTunes backup before performing the reset:
How to back up your iPhone, iPad, and iPod touch - Apple Support
When you are happy to proceed, you can perform the reset from iPad settings:
Settings > General > Transfer or Reset iPad > Reset > Reset All Settings
If the problem still doesn’t clear, the next step is to reset the iPad to factory settings:
Restore your iPhone, iPad, or iPod to factory settings - Apple Support
Otherwise, given your observations and concern, you might be best advised to seek assistance directly from Apple Support - and request a remote diagnostic test. You can contact the Support Team using the Support link at top-right or bottom-left of this page.
Alternatively, you can initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad - and you can explore your available options:
Genius Bar Reservation and Apple Support Options - Apple
