Chatty should ideally offer some obvious way of getting a more detailed error than "red cross" when sending fails
On the PinePhone, I noticed I can with latest modem firmware & mainboard & after switching to mobian (all three of which could be the cause, as well as any Chatty update since then) I can only receive but not send any text messages. What makes this a bit hard to investigate is that sending one just shows a red cross but not even a one-liner error of any kind that would indicate what is going on. So it would be cool if an actual error message was shown in the log, or some sort of obvious way to access more details about what is going on.