I have seen a lot of people commenting that they will see in the morning whether their issue is fixed. I have found a way that (at least for me) will show you whether the bug is likely to exist for you or not.
Go into your alarm list and hit 'Edit', choose an alarm and go into the 'Sound' menu. This is the list of sounds you can choose from to use to wake you up. I noticed that playing a sound and then hitting 'Back' to stop the sound triggers the bug so you should be able to work out whether the bug will affect you.
I also agree with the previous commenter who stated that the alert volume will reset to the same level as the game volume setting. That means, if you have your game volume set to minimum, the alert volume will set to minimum after playing the alarm sound. If affected by this bug, try to remember to set your game volume (the volume bar movable from the Control Centre) to where you want your alert volume to stay and this should do the job for you (I hope).