Yep, I've lost all 3 channels, online with Yt support now....
Update: it's a weird glitch, all external links to the channel page are showing grey header, and dashboard sub counts at 0. Yt tech confirms channels are fine on their end, with traffic at previous levels. they will escalate to internal support. I'm also not able to load m.youtube.com from a mobile Chrome Browser, and the Yt app is timing out.
Final update: all channels back up. Looks like a temporary glitch. i tried loading a dozen or so other kids channels, same grey screen. I wonder how many heart attacks there were around the world today, almost had one here.