If I settle a just cause termination out side of arbitration in the state of CA. Can I still sue my employer for wrongful termination ?

I am a shop steward 10 year employee with no write ups at all on my record or file . My union representatives business agent reported to my company I told him another employee touched me grabbed my butt. The other employee admitted to the action then claimed it was a mural thing and that is how our relationship at work was . He was suspended I was terminated. I was terminated because I am a Union rep I believe I have a case. The company wants to settle on outside
Of arbitration I don’t fully trust my labor union as I I can see the skid ales they made with my case. Also I have e mailed daring from 2018 compiling that my boss has it out for union stewards to prove
My wrongful termination. My question is if I take a settlement for just cause can is till sue in court for
Wrongful termination based on the grounds I was terminated because of my union status which is a protected status