Yes, “sprinklers.mydomain.com” nor “mydomain.com:1000″ both work in the browser, but neither work in the app.
Not sure if my response id getting through as this “post is awaiting moderation” for me.
URL Forwarding sounds like it’s an HTTP based redirect which I don’t think iOS would allow. I also noticed you said going directly to mydomain.com:1000 does not work. The only thing that’s possible is that you are using a self signed SSL certificate. If so, iOS application will not allow self signed certificates and will require you to get a legitimate one (eg. https://letsencrypt.org/).
Let us know if you are not using SSL and we can see what other diagnostics we can do to help understand this.
I am using a a letsencrypt SSL certificate on my webserver (mydomain.com:80 redirects to mydomain.com:443) but not on my opensprinkler (so that shouldn’t be the problem)
I am using Android 10, not IOS.
You said “mydomain.com:1000 does not work”, but it does via a browser (not the app).
Perhaps you can submit a support ticket with your specific domain names (unless if you are willing to publish them on the forum here), so that we can take a further look at the issue?