Endless stream of "Suspicious packet count xxx when bytes xxx for flow xxxx" followed by "Flow details for excess packet count " in Console
In my experience, the symptomsd &quot;Suspicious packet count&quot; is caused by a problem with the Apple Wallet. Go to System Preferences -&gt; Wallet &amp; Apple Pay (on Catalina, might be different on other versions of macOS) and verify that all your cards are still good.
You might also see errors like &quot;SEID Changed&quot; or &quot;Hardware has changed&quot; or complaints from nfcd if you have restored a wallet backup to a different computer (or a repaired computer that had its T2 chip replaced).