i don't understand why this only happens with the MBP. according to zoom's system requirements, the M! processor is supported for virtual backgrounds without a green screen. i'm wondering if it had to do with this snippet from their site. (but it's just a guess) my mac is intel based so i cannot test it.
Sending HD video when using Virtual Background
When using Virtual Background without a green screen, your outgoing video resolution is capped at 720p. To achieve 1080p when using Virtual Background without a green screen, you must meet the HD video guidelines and the following system requirements:
- Zoom desktop client for macOS: version 5.8.6 or higher
- Intel processor: 6 cores or higher
- Apple M-Series or higher