CDG-EWR 55 flight cancelled due to mechanical issues.

Got an email from UA offering me $925 in FFC. Does this negate the EU 261? Is it possible to get both?

I’m a 1k in Polaris. My husband is who is Gold in Polaris was only offered $650 FFC

Before I accept I want to know if I am
signing away the rights to my EU 261 compensation.

thx