I need somebody to fix the iphone login to my website

I have a website built using angular 5 app and my users can no longer login from their iPhones. I've been told it may be a timeout issue and the timeout needs to be extended. But may not be that, I'm not sure. All other devices can login successfully. I have a repository as changes need to be pushed into that so future people have the most up to date version of the website. Its built using AWS, Firebase And Angular 5 app. The front end is wordpress but I dont think this needs touching, it's a backend login issue. When iphone users try to type their email address into the login box it is just greyed out.

Thank you