You need to investigate the canvas app functionality issues.

Scenario: The testing team reports that one of the canvas apps is not working as expected. An error message displays as specific pages load.

A: The App checker is now available to help provide a clear list of formula issues in your app, and to provide items to fix to make your app accessible. The App checker is an area that the PowerApps team will continue to invest in, and build on in order help to make debugging, performance and best practice decisions an easier and more guided experience.

C: With the solution checker feature, you can perform a rich static analysis check on your solutions against a set of best practice rules and quickly identify these problematic patterns. After the check completes, you receive a detailed report that lists the issues identified, the components and code affected, and links to documentation that describes how to resolve each issue.