iMac waking from sleep after Catalina upgrade

[camner]

Before upgrading to Catalina, my 2015 27" iMac would reliably stay sleeping as long as I had manually put it to sleep from the apple menu.

After the Catalina upgrade, I'd say at least 50% of the time, the iMac wakes itself up if it has been sleeping from more than about 5 hours (so, quite often overnight).

Wake for Network Access and Enable Power Nap are UNchecked.

I ran the Terminal Command log show --style syslog | fgrep “Wake reason" after a recent awakening, and the last log entries were:


2020-06-11 20:59:49.029149-0700 localhost powerd[145]: [powerd:sleepWake] Wake reason: "<private>" identity: "<private>"

2020-06-11 21:51:50.752175-0700 localhost kernel[0]: (AppleACPIPlatform) AppleACPIPlatformPower Wake reason: RTC XHC1 (Alarm)

2020-06-11 21:51:50.752176-0700 localhost kernel[0]: (AppleACPIPlatform) AppleACPIPlatformPower Wake reason: RTC XHC1 (Alarm)

First, I don't know how to interpret these results.

Second, what is quite odd is that this last entry is on June 11. BUT, when I got up on the morning of June 12, I checked to see if the iMac had awakened itself, and it had not. At 8:30am on 2020-06-12, the iMac was asleep. BUT, at 10am when I went back again, it was awake.

So, shouldn't there be a log entry for the wake that occurred sometime between 8:30am and 10am on June 12?

Any help would be appreciated.

 

[Animaniac]

I have been trying to troubleshoot the same issue with my Mac mini after a clean install, resetting SMC, no wake on network access, etc. Logs look the same, and Mac wakes briefly every two hours. My research online seems to suggest this is a bag introduced in Catalina. Some hypothesize that it’s the OS checking for notifications. Disabling all app notifications does not fix this though. I think we just have to wait until Apple cares to fix this. I’d love to be proved wrong that there is a fix.

 

[camner]

I have been trying to troubleshoot the same issue with my Mac mini after a clean install, resetting SMC, no wake on network access, etc. Logs look the same, and Mac wakes briefly every two hours. My research online seems to suggest this is a bag introduced in Catalina. Some hypothesize that it’s the OS checking for notifications. Disabling all app notifications does not fix this though. I think we just have to wait until Apple cares to fix this. I’d love to be proved wrong that there is a fix.

Thanks for the reply. I, too, have begun to wonder if it is related to notifications. I have my untimed daily Reminders set to send an alarm at 9am, and I have noticed that it's often after 9am that I observe that my iMac has awakened from sleep (assuming I don't do it manually before 9am)