Container die when rtcwake is invoked

Greetings.

just set up a new Ubuntu 18.04 server and migrated my docker containers to it. I set the server to rtcwake to disk at mid-night and wake up in the morning. While all other Linux services wake up without any issue, my docker registry container doesn’t, meaning it crashed somewhere during the rtcwake process. Of course I can set the cron job to restart the container upon system wakeup. But I wonder why it shutdown while everything else gets restored healthily.

I’m sure I’m not the only one experiencing this. Would anyone please share some insight? Thanks much!