How do channels work excactly with AppFlow? App showing wrong build on first load

I built an app that I got into apple’s test flight and today I sent out the notifications to users to start beta testing, but for some reason it is showing the user the previous build. If the user closes the app and reopens the app it shows the current version.

In my config.xml file I have defined

<plugin name="cordova-plugin-ionic" spec="5.2.8">
    <variable name="APP_ID" value="my app id" />
    <variable name="CHANNEL_NAME" value="Master" />
    <variable name="UPDATE_METHOD" value="auto" />
    <variable name="UPDATE_API" value="" />
    <variable name="MAX_STORE" value="2" />
    <variable name="MIN_BACKGROUND_DURATION" value="30" />

Is something here wrong? Not sure why this is happening. This also was happening to me when I was testing on my own device using a development provisioning profile. I had to always open the app once, close it and reopen it to see the new build. Any ideas?