This is DEFINITELY an issue with the 5th generation iPad Pro. I am running IOS 14.6. I just received this iPad recently and set it up this weekend. Using it for the first time today on my Zoom workshop and sharing my iPad via cable (yes, approved apple branded cable). The buzzing sounds (about every 30 seconds) only when sharing my new 5th generation iPad in Zoom via the cable. If I remove the cable and use airplay and share in Zoom, no buzzing sound every 30 seconds or so. I have been using my 3rd generation iPad Pro (same software version 14.6) for the last year and a half and up to this weekend connected via cable and shared in Zoom with no issues. I just ran a test where I used my old laptop via the cable with no issues. So my only options right now are to use airplay with my new iPad Pro (this is NOT a solution, only a workaround) or just use my old iPad until Apple figures out this is their problem and they fix it.