iPad YouTube app: What does the number next to subscribed channels mean?

[emmx]

I've used YouTube a lot but I just recently started subscribing to a few channels.

On my iPad, where my list of subscribed channels is, next to each channel there is a number. I thought this meant that there were new videos on that channel, but every single channel that has a number has no new videos. If I close the YouTube app and actually properly quit YouTube and reopen it, the numbers reappear every time. Do these numbers mean there are new comments?

If it means there are new comments, that is extremely annoying because I don't want to individually go to each video and find what comments are new. I rarely read comments.

[SMELTN]

I thought it meant the number of videos in that subscription that you have NOT watched yet.