Lawyers, am I supposed to sign something I don't agree with just because it's "standard" and "I'm supposed to"?

I had an arbitration and signed the agreement. Received the first installment payment (smaller of the two) but before receiving the second one I have to sign a doent that includes stuff I do not find truthful or agree with, like the reason why I went to arbitration instead of suing is completely false and makes the person I am fighting look more innocent, and other conditions I don't agree with. My lawyer is getting frustrated with me and says it's standard, that I shouldn't read too much into it, sign it, get my payment and move on with my life. They've been holding the second funds which was supposed to be released in January until I sign it, like they're holding this to my head when none of it was brought up during arbitration and they already disbursed the smaller amount without this agreement being a condition. Can they really choose not to pay the rest until I sign and won't I regret signing something like that just to get paid? Do people really blindly sign these doents just to get their settlement and I'm being difficult?