Manual or boundary around not wanting to hear about wife’s ex?

My wife is currently going through another custody battle with her ex-wife.  After 4 years of this I have told her that I no longer want to hear about it.  She says that this is a deal-breaker and that if I don’t want to be involved then she doesn’t want to be with me anymore.

I actually feel that my decision is healthy and I have done it out of love for myself and out of a desire to stop enabling her to keep playing the victim with her ex (by being there to pick up the pieces).  But she has left and told me that it is over between us because I am not the supportive partner she needs/deserves.

I’m not sure what action I can take.  I thought that this was a boundary issue (me not wanting to hear about the ex/court case), but since I can’t think of an action I can take if she does the thing, for example, “If you continue to pressure me into supporting you with your court case I will…”?  So now I’m wondering if it is more of a manual issue e.g. “my partner shouldn’t share details of her issues with her ex with me”, or is this ok to want this? I’m now confused and don’t know how to proceed!