Hi I have also the M1 chip, found the solution here:
http://community.localwp.com/t/site-domains-setting-not-working-on-m1-macbook-pro/28771/12
That works for me,
I summarize:
- Close Local application
- Within the terminal, run this command to delete that router configuration folder:
sudo rm -r ~/Library/Application\ Support/Local/run/router
- Once that’s done, start Local and start a site which should re-create that router configuration folder.