I surfed through my available units at first, don't know why, sinced i surfed through a not so considerably fast rate, 7 of my units, just vanished right infront of my eyes the moment i pressed the consecutive "next" arrows .
It included 2 castles too..
and a pair each of mercs genoeses and knights and an inquisitor 
. I tried to recreate
the issue again with the permission of another player in another non bet match. After some experiments i got this. 
HOW TO RECREATE THE ISSUE
1, getting in an MP match
2, more than 25 something units alive and active to take action
3, initially taken some unit actions though
4, started surfing through next unit arrow at ~2 taps/sec
5, after a 5th or 6th unit , units currently selected seems to disappear randomly on click of the next arrow
=> noticing the issue, and took a moment lag in tapping next on response, resets the issue, with the disappeared units gone forever.
