Security Update 2020-005 High Sierra fixed a bad bug. The release note doesn’t say anything about it, but I observed the following change on my 2017 iMac 5K running macOS 10.13.6 High Sierra:
In July 2020, I installed Security Update 2020-004, 10.13.6 High Sierra (17G14019). After that, if my iMac sleeps and then wakes up, at first it works fine, but after a few minutes, Internet connection disconnects itself. The PPPoE menubar icon shows the disconnected status, and if I use that menu and select the ‘connect PPPoE’ item, it tries to connect, but fails. The only way to connect to the Internet was to open System Preferences, open Network pane, select ‘PPPoE’ from the sidebar, and then click the ‘Connect’ button. Then the Internet connection (Fiber-optic connection by a Japanese ISP) would come back. But then if my iMac sleeps and wakes up, the same thing would happen again.
This was the situation with Security Update 2020-004. (I had NEVER seen the problem before that.)
On Friday (September 25, Japan Time) Security Update 2020-005 High Sierra (17G14033) came out. I installed it. After that, now that 50 hours have passed, but the problem never occured again. Internet connection is 100% reliable now. Somehow, 2020-005 must have fixed something about my PPPoE connection.
Apple’s macOS Catalina 10.15.7 release note says:
- Resolves an issue where macOS would not automatically connect to Wi-Fi networks
I guess this might be related…?