Hi @cofordpa ,
Have you solved your problem?
The "Delayed Load" preview feature within PowerApps Advanced setting is used to speed up your app's start time via setting on-demand expression call.
There may have some unknown issue with this Preview feature when you type too many formulas or incorrect formula within the OnStart proeprty of your app.
If you have solved your problem, please consider go ahead to click "Accept as Solution" to identify this thread has been solved.
If the issue still exists, please consider turn off the "Use Non-blocking OnStart rule" option and "Improved app rendering (final validation)" option within Advanced settings of App setting, then re-publish your app, check if the issue is solved.
Best regards,