I have EXACTLY this same problem on my iPad Pro 12.9”, only worse - as notification alert sounds are also not operational.
No sound when a imessage arrives, or a facetime request is received.
I get notified visually on the screen to both, both no sound locked or unlocked.
Keyboard clicks are on, and have been cycled on and off. Do not disturb is off.
iMessage and facetime have alert sounds enabled and assigned.
I first noticed it this morning when I plugged in the iPad - no sound - normally it makes some kind of ding.
I did update several apps this A.M. prior to plugging in.
I updated youtube, photoshop express, outlook, microsoft translator, espn: live sports and scores, kik, bbc news, and api healthcare.
It is a 2nd gen., running ipadOS 13.6, with 27gb available.
I have completely shut & powered down the iPad three times to no avail.
Help!!
I use this as a phone, these sounds are critical to me.
I’m beginning to believe this is a software issue.
patch me, pls
thnx, jon