Visiting banking app page results in almost white screen on iPhone

I try to verify my identity in a new banking app. But every time I go to that page, I get just a white screen. Not entirely white, I can still close the window and I see the address on top. But the prompts to follow are not visible. Is this perhaps something in my settings? I looked everywhere already but could not find a remedy.

I use an iPhone X.

Thank you for helping.

[Re-Titled by Moderator]