iPhone stuck on sign-in or sign-up screen of Zoom

Hi, all. I'm helping a friend with Zoom. She has not signed up for a free account yet. I send her my meeting link and when she goes to the link, she's taken to a screen that offers four pages as reported by VoiceOver including the sign-in or sign-up screen. None of these can be activated by a double-tap with VoiceOver. Neither can we activate the Settings button. We are not prompted with any permissions requests for the microphone or camera. We're just stuck in a holding pattern and she cannot go to my Zoom meeting. Any ideas why this is happening? I did get a couple people out of this fix by adjusting the screen from near 0 to a brightness to around 50%, deleting the app, and then re-installing. However, this did not work for her. We have deleted the app, re-installed, etc. and there's no way to click on a meeting link and run zoom for the first time without being asked to sign in or sign up. She has sufficient wi-fi and cell signal. Any help would be appreciated. One should not have to create a new account to go to a zoom meeting. Thanks much.