I got an answer from Meraki Support: "We have re-created this issue in a lab environment, It appears that the Apple TV NIC tries to negotiate a half-duplex switch mode in sleep mode. I can confirm that Cisco Meraki is currently speaking to Apple regarding this issue."   So hopefully Apple will update the firmware or Meraki figure out a workaround for this issue soon. ... View more

Can confirm that I have the same issue on my MS120-48LP running MS 10.45. I have 7 AppleTV 4k connected and all of the switchports reports very high amount of CRC-errors as soon as the AppleTV is not in use. ... View more