WhatsApp issue when playing voice messages on fast speeds

Hi.
I really like the ability to play voice messages on whatsapp in fast speeds, but at least for some devices there is a small issue.
If we try to lock the device, the voice message stops playing untill we unlock again.
In fact, we don't need to unlock the device, just to wake it up by pressing the side button. As soon as the device locks again, the message stops.
I have got the iphone xs 512 gb, with the latest ios 15.3.1 and the latest whatsapp installed.
On normal speed, everything works as expected.

Also I am wondering what is the best way to report issues to whatsapp?
Have they got an email address, a contact form or something else?
Thanks a lot
Nikos