I started by checking the ownership of the videos on YouTube (through Content ID). All recent videos are claimed by emails on a domain entonegroup.com. The domain itself yields nothing as it's registered with an extra privacy option.
However the email leads to a lady that works for Entertainment One that also advertises [0] the ownership of the content.
I also checked the earliest videos of Peppa and it seems like they were produced by a different individuals, which would suggest that, at least this show, was acquired by Entertainment One.