Cbeebies breakdown slide appears just before Four startup.
Did anyone else get a cbeebies breakdown caption for around 3-4 seconds before BBC Four's "BBC Four begins at 7:00" caption came up? I was on the BBC Four feed waiting for Four to start up and after the "BBC Four begins at 19:00" caption faded out there was a second of Cbeebies closedown and then black screen for around 5-10 seconds, followed by the breakdown caption. Then Four started up as usual. I didn't think to check the Cbeebies feed to see if the breakdown continued on there, but the regular off air caption is there as of 7:07.
CBeebies and BBC Four share a video stream, so just before 7pm the video going to the encoder is switched from CBeebies output to BBC Four's output. At the same time the ID on the video stream is changed, so that it disappears from CBeebies' channel number and appears on BBC Four's channel number.
The two aren't perfectly in sync, so it's not unusual to see a second of BBC Four's startup slide on CBeebies' channel number before it switches, or a second of CBeebies' close down on BBC Four's channel number.
For some reason BBC Presentation (Red Bee) put the breakdown captions on the output of their channels when they're off air, so what happened here is the video stream switched over to BBC Four's channel before Pres faded out CBeebies' closedown slide, and then Pres switched the video to BBC Four's output slightly late so you got to see the breakdown caption coming out of CBeebies' output.
The reverse happens just before 6am, so it's not unusual for BBC Four's breakdown caption to appear on CBeebies for a brief moment.