I can't believe 409A valuation for option grants is even legal

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Illustrative scenario prepared by my practice.
For informational purposes only. This is not legal advice. Laws vary by jurisdiction. Consult a qualified attorney for advice specific to your situation.
Hypothetical question

English isn't my first language so bear with me. I'm dealing with a situation and need some guidance.

409A valuation for option grants. I've been dealing with this for about 15 weeks now and the situation isn't improving.

I have already consulted briefly with a lawyer but the other party is not cooperating.

Do I have a strong case? What should my next steps be?