Hi, ralphkobby1.
I'm Jen, I'm also using the mobile app version of Microsoft Edge just like you. I'm not working for Microsoft but I'd be happy to help you figure this out.
I have checked the website from my phone and had no issues accessing it. Have you tried clearing your browser's cache, cookies, and browsing history to see if it helps? You can do this by tapping on the 3 dots then Settings > tap on Privacy and security then Clear browsing data > select Browsing history, cookies, and site data and cached images and files then tap on the Clear data button. Close then relaunch the app and check if you're able to view the site.
I hope this helps. Feel free to share how it went.
Kind regards,
JC