PowerCore Slim 10000 PD not charging iPad pro 11inch

Just got 2 PowerCore Slim 10000 PDs. Charged them fully, all blue lights on. It will charge my iPhone, but not my iPad Pro.

Starts to charge briefly then stops, says not charging. Both units the same result, using either Anker supplied or Apple usb c cables or usbA to usb c.

IoS 14.4

Any ideas why? My need was for phone and/or iPad and product description seems to indicate it should work.
Thanks

Hi, did you fix it? I am having the same problem! Cheers