Hi 
, welcome to the Netlify forums! First did you see this guide on debugging redirects? I strongly suggest you give it a thorough read through and see if this fixes your problem.
Next, did you make sure the _redirects file is in the correct location and is being deployed to Netlify? Did you define your redirect to the the config.toml? If so take it out it’s not necessary.
Finally, It would be helpful if you attached your repo as well or build/deploy log.
Thanks so much!