SharePoint Ribbon button disappears intermittently (the button is used to launch an App)

I have used the following code in a custom action to register my ribbon button (when clicked navigates to my application)

Id="a39581AF-2E1D-4FE9-AE1C-6C7FDB2A2C12.NJAppList"
RegistrationType="ContentType"
RegistrationId="0x"
Location="CommandUI.Ribbon"
Title="NJTestApp"
Rights="ManageWeb">

<CommandUIExtension> .... </CommandUIExtension>

After I add the app to my O365 site, the button appears as expected in the list settings and works as expected. But after few days of using the app the button suddenly disappears. The only alternative solution that I was using to get back it is to remove it and add the app again. I was wondering if anyone has come across this weird issue and have found a reason.