deeplink 404 error on linux server

I have deeplinks working locally but when I try on our on premise linux server, I am getting a 404 error.

I have set up the request handler - /link/ is set in the yaml file and the link location set in the config file. I have used deeplink in other apps on our server successfully and have the yaml and conf set up similarly.

I am logging in as admin first before trying the link url so not anonymous and am using the same login as when I try locally.

I'm not sure what else to check. 

Thanks,

Tracy