it's a webview issue in the sense that webview isn't a browser.
there are a number of "errors" reported in some of the .js files used by the website. if you use the developer's tab on a desktop version of chrome, you will see them all. webview, being related to chrome, refers to some of them. chrome may or may not chose to ignore them and render what it can. webview may behave differently. in other words, you may or may not see a page. webview is not a substitute for a browser. (if you pump the url in chrome on your device, you'll see the page.)
note: chrome (and webview), firefox, edge, and the like have their own rules. just because some webpage is available doesn't mean it conforms to all the browsers that will render them. this has been an issue since the day more than 1 browser appeared. whatever the actual errors - if any - are, chrome is ignoring them, but webview isn't.