Why is Big Sur messing with my 2015 MBP? Last week I updated both my 2015 MBP and my 2019 MBAir to Big Sur. Having intermittent WIFI glitches on both and with the MBP, I cannot stream any video at all. Anyone have any ideas? Do I need to revert mack to Catalina for my MBP? App & System Services Core OS macOS 0 0 113 Dec ’20