Update: Fusion Applications Cloud Using Chrome Browser
As of 14 July 2020, the Chrome browser cannot open external application pages embedded in Fusion Applications Cloud. Chrome browsers changed their behavior to enforce more privacy-preserving defaults for cookies called SameSite. A similar plan is already in place for Microsoft Edge and Firefox browsers, both currently supported by Oracle Fusion Cloud.
For more details, please access Cannot Open External Application Pages Embedded In Fusion Applications Cloud Using Chrome: Doc ID 2683816.1.