MIDI Thru Does Not Work With iPad Pro 12.9"

MIDI Thru does not work with the iPad Pro 12.9". I just verified this by using the iPad Pro versus an iPad Mini 4 with two different keyboards: a Yamaha Piaggero NP-32, and a Yamaha Montage 7.

On the iPad Mini 4, MIDI Thru works as expected with both keyboards. On the iPad Pro 12.9", MIDI Thru does not work with either keyboard. I used the same Cubasis project on both iPads.

Cubasis 2.3, iOS 11 (latest version). I’m hoping this bug report will make it to the people who can fix it

Double post, please read here:
https://www.steinberg.net/forums/viewtopic.php?f=183&t=126698