for what it may be worth:
from
https://developer.android.com/develop/background-work/background-tasks/broadcasts
"If you declare a broadcast receiver in your manifest, the system launches your app (
if the app is not already running) when the broadcast is sent."
this is an exception to the rule. (the rule being you can't start an activity from the background). an alarm broadcast can launch an app when the alarm is triggered.
judging by the service's only being required for an hour, i would think it would continue running if the user simply started another app (as opposed to, eg, swiping to force killing it). i listen to the radio (background) in an android device for around an hour while flipping back and forth between other activities. i suggest rebuilding the app (as is) under b4a 13, running it and coming back after an hour to see what has happened. i would also test by running the app and then launch some other apps to see what has happened to the monitoring service. and go from there. based on what little we know about the app, there may be nothing that currently causes it to fail under android's ever-changing rules. i imagine a user starting the app to set the service in motion and then starting some other app, maybe to check email or to listen to the radio, while the monitoring service runs its course. i would expect that to occur without incident. i don't image the user starting the service and then force killing the app. if that happened, they restart the app and not kill it this time. i mean, really, how much are you supposed to do? if monitoring is supposed to go on all day, then you run the risk of its being killed due to battery preservation issues. more confusing than receiver vs service is the matter of battery conservation.
before looking into added functionality, i would like to hear whether the apps runs as is under android 14 and address that first. if an app has a service that's supposed to run for 1 hour fails to do that, in general, there isn't any particular signal given to that effect. (after the tree falls in the woods, somebody has to come by later to see if anything has happened.) how you deal with that requires knowing more about what's expected of the app. must the service be started at some specific time or all is lost? can it be run at some later time in the event something prevented it from running at the assigned time? perhaps a foreground service is needed, although there is no guarantee that the os does not kill the app. an alarm could trigger a receiver to make sure the service was running (not an alarm app; this is an alarm broadcast receiver). an alarm broadcast might even allow the user to forget about starting the app. if the app runs fine now, then adding a receiver shouldn't be too difficult. if the app doesn't run correctly now, then there's no sense adding a receiver that continues to make it run incorrectly. i use receivers (eg, for sms management or telling me when a usb device has been plugged in), and i've tested with a receiver launching an app that was not running at all. i'd like to know what i don't know before trying to suggest a solution (to a problem that i'm unaware of).