Cannot dismiss keyboard in Content Server-settings

I have an iPad Pro and an iPhone XR. On my iPad works everything fine after I set the Content Server address in the „normal“ setting and under advanced. Just https://mydomain.com without a port.

On the iPhone it won’t work because on the IP address the „enter“-button is a next-button and on the Port it it is a done-button. But the done-button is greyed out when I do not enter a port. But the app does not allow to enter a port when you have a URL set. And there is now way to dismiss the keyboard like other apps sometimes have.

I bet if I can connect a Bluetooth-keyboard everything works fine since the soft-keyboard is not shown and I can hit Ok in the dialogue.

Please fix this bug so that people without a Bluetooth-keyboard can use the app on an iPhone