Hello,
Which direction is the MIDI info traveling: are you using Drumagog's MIDI input (sending a MIDI track's output to Drumagog, as in using it like a synth), or the opposite with Drumagog's MIDI out (having Drumagog generate MIDI to trigger a MIDI device on a MIDI track)?
If you are using Drumagog's MIDI out keep in mind you may need to use a 3rd party MIDI virtual interface/loopback, like MIDIYoke (http://www.midiox.com/myoke.htm) to successfully route the MIDI signal out and back to your MIDI track, as many host applications either ignore or have a difficult time routing MIDI out from a plugin.
Also, Samplitude has caused some issues in the past if there wasn't continuous audio data on the audio track hosting Drumagog. If there was a gap in the audio info it would kill Drumagog from processing, even while the project was playing (There are some older threads on this board discussing this). I'm not Samplitude-savvy enough to know if that's changed in Samplitude 11; it would be a setting/option on plugin monitoring inside Samp that allowed plugins like Drumagog to keep running even when there is no audio on its track.