In an organisation that used strong authentication to access SharePoint we are using SmartCards to do so. Acrobat is currently not correctly handling the login, so when using strong authentication you cannot access Sharepoint. According to Adobe Support this is not a bug, but a missing feature.

When trying to add a Sharepoint in Acrobat it is expected that a browser window is presented to ask for the credentials after entering URL and Username, in this case to ask for the SmartCard PIN. A browser window is indeed opening, but is instantly being replaced by a dialog showing, that this resource cannot be accessed and you should contact you administrator. This is most likely due to the fact, that only access by SmartCard is allowed and none is found by Acrobat, even though it is available.

The resource CAN be accessed, other applications can do it and you can access Sharepoint right from the browser, too. According to our research and experiences with other applications FIDO support must be enabled to access the SmartCard. In addition, Apple already provided more details to help:
"In Safari (and SFVC) - (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential *))completionHandler is handled for the client.

However for WKWebView (what is apparently used here), the client needs to implement that delegate themselves. You should implement that method and use keychain methods to get what’s on the smart card."

This missing feature is heavily disturbing our workload (over 5.000 Macs affected), since we are currently moving to Sharepoint.