What devices should do, and what they actually do, are two very different things! As you've probably heard me mention countless times, many of those screens get information in a proprietary manner directly from the modem; apps like SignalCheck can only get what the OS is reporting.
I did find your earlier reports, and as I guessed, the OS was reporting valid signal strength. I will try to figure out a solution.
Hey Mike—another dual SIM bug. If one SIM loses service, it doesn’t disappear from the app.
I’ve seen this a couple times—my Dish SIM will lose service (confirmed in service mode), but SCP won’t stop displaying -115 or so. And it logs a data point at that signal every time the location updates.
Along the same lines, I have a custom trigger set up for 313340 (Dish), and the custom trigger keeps firing when this is happening.