Frustrations with Messages Sending Mechanism – Am I Missing Something?

I’m reaching a breaking point with Messages. Here’s my gripe: when I’m out of mobile signal, the Messages app stubbornly tries to send via SMS. Even when I later connect to wifi, it refuses to default to iMessage and persists in its SMS attempt.

In contrast, I like WhatsApp’s approach. Even though it lacks SMS capability, the app waits until a connection is available, then sends the message. No fuss, no confusion.

To provide some context: I commute via the London Underground daily. While it lacks mobile signal, wifi is available at the stations. The same challenge arises when I’m on a flight and want to queue up my message replies. It seems I can’t rely on Messages to send them once I regain signal.

Is there a setting or tweak I’m overlooking that could make Messages more user-friendly in these situations?

You can turn send as sms off, have you tried that?

I haven’t! Is that new? I’ll give it a go.

EDIT: it doesn’t work well at all - it just errors if I’m not on signal.

I’ve had a problem with Messages twice, the last time February 2020. I was in an area with poor cellular coverage and while there was a data connection it had basically no bandwidth.

Messages could not connect via data and refused to switch to SMS. Turning off cellular data didn’t help so I was unable to send or receive any messages. OTOH members of our group with Android phones were able to occasionally send/receive messages.

This happened both times I visited the area. The first time I was using an iPhone 6S, the last time I had an 11. My guess is Messages “doesn’t know when to quit” when it encounters some areas with poor data. On my next trip I’m taking a Garmin inReach and/or an Android phone as backup.