I have installed the 301Redirects version 1.9 into Sitecore 10.4 and everything works except when redirecting on found items. I followed the readme as best I could (links don't work!). But I found this which pointed me in a direction: 99419af
Added the item to Redirects folder field Items Which Always Process Redirects and used a Redirect Pattern, but no joy.
The only difference in my set up is that the Redirect Module & Redirects folder were moved to a Global Settings folder under content. Config was updated to accommodate this.