Calendar Sound Notifications

Hi

I’m trying to change the sound on calendar notifications. Looking on previous messages, I’ve turned these sounds off & notifications then did hard reboot, then added revised sounds & notifications but it’s not actually changed, when a calendar notification plays.

It currently plays quite a long notification & my boss gets annoyed - so want to change to a shorter one.

Other sounds can change, like ring tone & turning on off locked screen.

Thanks in advance