iMessage's bubble is green on iPhone, why?

Ok.

I’m wondering if you could both switch off mobile data first and have just wifi enabled and check what happens when you both send an iMessage to each other. see if it’s blue on each other’s iPhones.

Have you gone over to the neighbour house/appartment and checked your iMessage received and sent, and theirs, plus neighbour go to your house/appartment and checked iMessage sent and received (both of you)

Then try switching off wifi, and turn on mobile data only and send each other an iMessage and see what happens.

Are both of you always having both wifi and mobile data enabled always?

Note:

I remember my aunt having iPhone and myself, I used to keep letting her know that iMessage was not sending blue my end to her, but was sending to other people I knew. My iMessage was sending as the Green Bubble!

After troubleshooting with her over the phone, we fixed it!

Problem was: She had her iMessage switched OFF in her settings!

All was good again.

Some time later I sent her a text and it happened again, and it turned out that she had turned off her mobile data because she didn’t want to chew up her data… and for some reason her iMessage setting wasn’t working through their home internet wifi. So my iMessage was green bubble again and thereafter!

I am Mentioning this just in case you figure out something is similar going on with your end or your neighbour end? Maybe your neighbour has done the same thing unknowingly.

Ask neighbour to go into the settings and iMessage and make sure they have “iMessage “ switched ON.

If everything else fails perhaps both of you log into the Apple Support app and put a request through for some advice/troubleshooting with customer support.

la-dee-da wrote:

I presume because the message is being sent via SMS but WHY?

1- both users have iphones

2- both users have imessage enabled

3- imessage and icloud are available

You missed one requirement: both users must be connected to data (either WiFi or cellular). If either or both are not connected to data, the message may be sent as SMS.

Any add-on security apps, or any add-on VPN client apps, or any firewall security or filtering in use?

(Remove any add-on security apps, and remove any add-on VPN apps, force-restart the iPhone, and try again.)

I have on rare occasions had this happen when sending text between two iPhones and iMessage enabled both ends.

If my friend in USA has his phone switched off or dead battery then my texts to him are green instead of the usual blue.

Occasionally it happens for no apparent reason and then it suddenly becomes normal iMessage again.

i haven’t actually looked into it because it seems to quickly resolve itself.

la-dee-da wrote:

We are next door neighbors. Both always on cellular or wi-fi. Thanks.

The fact that you have them enabled doesn't necessarily mean they are connected. But, that's the only thing I can think of.