Some MIDI grooves in Mediabay is not working

When I go through several menus, Mediabay -> Loops & Samples -> AM Signature Drums… and click any sample sound(for example, 8BT_1_Clap1, ABT_1_Clap1, etc). then it sounds well.

But when I click a MIDI groove(for example, 8 Bit Kit 1 AM Beat 1, Ambient Kit 1 AM Beat 1, etc). NO sound at all.

It seems that all MIDI grooves in the other menus except ‘AM Signature Drums’ works well. The only MIDI grooves in ‘AM Signature Drums’ doesn’t work.