Na xda poruszony jest ten problem.
Naoisalem w tej sprawie do HTC, podlinkowałem wątek na xda i po kilku dniach otrzymałem aktualizacje naprawiającą problem z mikrofonem
https://forum.xda-developers.com/u12-plus/help/android-pie-speaker-call-microphone-t3957849/page9
Aktualnie HTC aktualizuje wszystkie telefony
dodana zawartość
"We have already started developing an update for your phone. Once available, it will be delivered to your phone through an over-the-air (OTA) process and you should receive a notification indicating the update is available for download. We expect the update to be available by the end of May. We appreciate your patience as we've worked to quickly address this issue.
Thank you"