Panel/Assignment Breaks

Before reaching out to my CDO, what's the lowdown on breaking an onward assignment post-paneling?

Background - paneled for an onward for DC. Tried for overseas but nothing came together so settled for my plan C DC option. There's a curtailment in the same bureau (overseas position) which will open up a position that would be a very good fit.

Can I pursue it or am I locked in? It's the same bureau, so I suppose the AO's won't be happy about this.