Alarm sound very quiet

Do you have iPad Pro with Face ID? When the Alarm went off, were you looking at the iPad? If yes to both, you have Attention Aware enabled on the iPad. Devices with Face ID will reduce the volume of incoming tones like Alarms, Ring Tones as soon as the True Depth camera knows you are looking at the device. This feature can be turned off, but if what I have described is your issue, it's actually a great feature, to be honest.

Hello,

Just so I can help verify what you have done, have you gone into Settings -> Sounds and increased the volume slider for Ringer and Alerts? iPad has two sounds systems. One for multimedia playback, like movies and music, and another for alerts, like ringers and alarms.

If you are certain the ringer volume is turned up all the way, have you tried restarting your iPad? This can be done by pressing and holding the Sleep/Wake button until you see “Slide to power off...” appear. Once your iPad is off press and hold the Sleep/Wake button until you see the Apple logo appear.

Glad to help. It is actually a great feature. One the people in my office great appreciate as it works the same way on iPhone Xs Max!