A couple things to note. In addition to what @angus.black posted, there is a delay in writing to the SD card, because the full minute hasn’t finished processing in the buffer, so it is possible to go to the Playback before the 1-minute recording has been saved. <= If you go immediately from the cloud notice to playback it simply may not be there, yet.
There are cases where you get notifications, but don’t get SD card recordings (Playback).
There is discussion of a fix on its way in that second thread.