Issue may caused by the actions that firmware jump from boot to app

I am using nordic 52840 for produciton development
After software jump from boot to app, then app run ok, but after 8 mins ,it went wrong(uart can not reply anymore).


we did another test: run app directly without boot, then, the application can run a long time without any issue.

The actions are done before jump from boot to app, some uninit actions are executed in order to make the peripheral return it's default status. 
the questions is that: 

         1. when jump from boot to app, the resource need to be released to it's default value, But how can we know that all peripheral are ok for app?
            Is there a simple way(execpt software reset), like a function or command that we can use to release all peripheral for app?

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