I noticed today that it's not working on Channels DVR and online via browser or app. In Philo & spectrum app it's ok.
It's most likely the same as previously reported:
https://community.getchannels.com/t/tv-everywhere-a-e-stream-not-available/26558/47
(A&E and History are both owned by A+E Networks. The issues are already discussed in the aforementioned thread.)