Insurance offered $9,200 less than KBB for my totaled truck and refuses to share their valuation report. Is this normal?

Some kid ran a red light and t-boned my 2019 F-150 last week. No injuries thankfully but the truck is done. The other drivers carrier accepted liability on day 1 (they had to, witnesses everywhere) and a week later sent me a settlement offer of $19,400 ACV.

Problem is my truck is a SuperCrew XLT 4x4 with 58k miles, well maintained, all service records, two new tires last fall. KBB private party for my exact trim and miles in my zip is $28,600 to $30,100. Even trade-in value is over $24k. Their offer is below trade-in.

I asked for the valuation report and the adjuster said its an internal CCC ONE document and not something they share. She said I should just trust it. Friend of mine in another state said when his truck was totaled he got the full report with comparable vehicles listed and was able to dispute it. Anyone been through a CCC ONE valuation dispute? How do I get them to come up to a real number?