Synergies are fun and useful tools that add a bonus layer of group interaction and player utility to the game, but only one synergy will show up and/or can be activated at a time. Many times there will be multiple synergies available but you may not be able to activate the specific one you need until the one showing up for you either expires or it is used by another member of your group.
I think it would be very helpful if there was some kind of synergy prioritization setting we could open to view every synergy available in the game and organize them in order of personal preference, so that the most desirable synergy abilities will always take precedence over the ones we set lower on the bar.