Miss Puppet's Attempt For Forgiveness - II

Ravenna's displayed submissiveness and coquettishness were shattered by Ansel's words, pointing directly to the core issue—if Ravenna truly considered Ansel's interests, why did they part ways three years ago?

Either, as Ansel suggested, Ravenna's current behavior is sheer pretense, or...

There must be something that, despite Ravenna's considerations for Ansel, prevented her from standing by him.

Another possibility is that Ansel had broken off with Ravenna abruptly without saying anything, but that's implausible because Ravenna is clear that without a solid reason, she would never genuinely see Ansel as a traitor.

Indeed, if she is now willing to entertain the audacious thought of assassinating the empress due to threats against Ansel, then her past self... had no reason to lack such resolve.

So, what was the fundamental reason for their fallout?