I have had the same problem. I am in the process of sending mine to The Mountain Boot Company in Newcastle. They seem to be optimistic about the outcome.
I know of at least 3 people who have received new boots from Mountain Boot Co, broken zips. I have another friend, less successful, you should speak with the Bird.....
Try contacting Scarpa - I had a pair of 2021 Phantoms that broke on the zipper last season, sent them an email last summer asking if I could pay to have them repaired and full credit to them even though the boots were outside warranty period and I had no proof of purchase they sent me a return label saying they'd look and 7 days later a brand new (updated version) pair of boots arrived at no cost. Cannot fault Scarpa for their customer service 10/10