I have this issue with iphone12 and iPad pro.
The volume of the timer and alarm is very, very low. Sometimes it starts loud for a couple of seconds and then becomes very low. I’ve set the volume to max in Settings/Sounds.
iPhone 12, iOS 14
What I have found to work, is deleting all your alarms, especially if you have a lot. Sometimes, the alarm doesn't ring, this used to happen to me as well, I just deleted all my alarms and made only three alarms that I use mainly. If I ever need to add a new one off schedule I do that and delete it after use. Again, this worked for me so maybe it is worth a try.
Thanks KV2808. The phone is brand new, so this is the first alarm that I’ve set on it.
Problem solved (by my son - thank you). The devices go to low volume if you are looking at the screen.
Timer and Alarm volume
