I believe I have seen the same thing with a Mid 2015 11,4 running catalina. Not diagnosing further because I could not find a reason for it fast enough and not sure if it really had an impact at the moment…. but could you try the following
sudo sysctl net.link.generic.system.hwcksum_tx=0 sudo sysctl net.link.generic.system.hwcksum_rx=0 sudo ifconfig en0 -rxcsum in reverse … to restore the settings sudo sysctl net.link.generic.system.hwcksum_tx=1 sudo sysctl net.link.generic.system.hwcksum_rx=1 sudo ifconfig en0 rxcsum If you have some specific tests to run I would be willing to run them here on Big Sur with the same laptop but I have nothing now that runs Catalina Wireshark used to in Catalina rack up cksum errors a lot while these were all at their defaults. > On Oct 29, 2020, at 08:23, Mark Tinka <mark.ti...@seacom.com> wrote: > > > > On 10/29/20 15:04, Cory Sell wrote: > >> Might be worth disabling each AP to see if there's one out there having an >> issue playing nice with the MacBook. Also try different combinations of two >> APs working together. It's possible the MacBook is flip flopping because the >> power levels are fighting each other. > > Tested all that, as well as dropping Tx power levels on each of the AP's to > Low so that there isn't any power coming from any other AP (despite being > quite far, already). > > And to confirm, when the laptop locks into an AP, it doesn't try to join > another one. When in range, power is very good (between -37dB and -52dB). > When I walk away, that AP becomes too far (as bad as -80dB), but the next one > close by is far better (same good values as before) and laptop connects and > sticks to that. > > Again, only impacts Catalina. No other Apple device, or the Windows PC that > is on the same WLAN. > > >> Does the Mac have this issue at your local coffee shop or another >> establishment with Wi-Fi? You can try to rule out the AirPort card in the >> Mac itself. > > Never tried, I generally work from home. If I'm out, it's faster to tether to > my 4G service rather than any public wi-fi. > > Mark. -- J. Hellenthal The fact that there's a highway to Hell but only a stairway to Heaven says a lot about anticipated traffic volume.
