Youtube data API - mismatch between number of videos in channel statistics and "uploads" playlist

I need to retrieve full set of videos from particular Youtube channel.I do this using Youtube Data API v3 and google-api-python-client package.

Basically, I get ID of "uploads" playlist, then use playlistItems.list API method. The problem is, Youtube API doesn't seem to return full list of videos.If I try to get channel statistics ( using channels.list method ) it says channel has 32356 videos. However, playlistItems.list returns just 19989 videos.

Channel ID in question is UCdl_gZZR6BtKi45eHFGAduw. When I perform channels.list requestit returns statistics.videoCount = 32356. However, when I use playlistItems.list methodit says there are 19989 videos in total ( pageInfo.totalResults field ).

So I'm wondering why such a big difference between channel stats and number of videos? I was thinking that maybe some videos are private, or were deleted and channel stats wasn't updated, but such a big difference feels excessive.