Combining DNS 301 redirect with Webflow 301 redirect

We purchased a competitors domain and have created a 301 Redirect in our DNS to redirect all traffic from that domain to ours - that’s working fine.
The problem is that the old website has some URLs with underscores in them (e.g., about_us). Webflow does not allow underscores in slugs, so I created a 301 redirect in Webflow to redirect /about_us to /about-us.
Now if I go to olddomain.com/about_us, it redirects to just newdomain.com, and not to Parked at Loopia.
What’s the proper way to redirect all traffic AND handle page redirects for pages that have underscores? Thanks.


Here is my site Read-Only: LINK
(how to share your site Read-Only link)