Email Open Rate Drop After DMARC Update: Possible Causes?

Hey! Recently updated my website to squarespace and had to update DMARC yesterday via Beehiiv. Noticed by open rates for my newsletter today went from 61% to 10% - do you know what might be causing that? On Dmarcian, I saw my domain (Sfirl.com) had a "Great Job! You have a valid DMARC record that provides visibility into the entirety of your email program(s) and helps ensure you meet email sending best practices"