It's confirmed that issues were caused by some wireless signal interferences between/amount USB wireless devices (especially for USB+Blooth wireless combo devices) and the USB/Thunderbolt ports on Mac systems after firmware and OS upgrade of Mac systems.

Solution: Please replace your USB+Blooth wireless devices with wired/USB only devices, before Apple or Logitech may release a fix for this problem.

It's confirmed that issues were caused by some wireless signal interferences between/amount USB wireless devices (especially for USB+Bluetooth wireless combo devices) and the USB/Thunderbolt ports on Mac systems after firmware and OS upgrade of Mac systems.

Solution: Please replace your USB+Bluetooth wireless devices with wired/USB-only devices, before Apple or Logitech may release a fix for this problem.