Ingress - URL Rewrites appear to be broken

#1

I seem to be facing a similar issue to this:
URL Rewrites broken on Ingress

I have a Kubes cluster running on Azure with DNS via CloudFlare.
The Ingress has a rewrite rule setup, via the usual annotation
nginx.ingress.kubernetes.io/rewrite-target: /

For some reason the rewrite rule doesn’t appear to take effect.
Wondering what might be going wrong here?