I have a Samsung S10 but I also had this problem with my s8. I used to send texts over the wifi in airplane mode with not issues as long as advanced calling was activated. However in the last 6 months, this only seems to work for the first few minutes after a restart.
I put the phone in airplane mode, turn on the wifi, verify the wifi is properly connected and then attempt to send the text. On my new S10, I automatically get a pending message that states it can't send in airplane mode. I select restart and restart the phone. After the phone comes back up, it shows that the text is sent and I have been told that the received did receive it.
This is a very annoying situation. As a results of this issue, I have to restart my phone many times a day especially if I am expecting a text. Is there a setting or system change that is causing this to not work. I was able to use this function, since advanced calling was first created, why doesn't it work now?
Thanks for that confirmation, Bookworm222. The native messenger does not have the ability to text over Wi-Fi, however, Message+ is capable of this function. I am eager to figure out your messaging issue. Can you tell me more about who you are attempting to text (singular person or group) and what you are trying to send (text or picture message)? What software version are you on? You can check here: http://spr.ly/6605EZWzF Why do you prefer that the texts are processed through Wi-Fi versus the cellular network? Please check your Wi-Fi speeds using this link and provide me with a screenshot: speed http://spr.ly/6606EZWz2
The native app absolutely can send messages over WiFi. I can confirm this by turning off airplane mode (up in a plane it won't connect to the ground) and the messages instantly send. There's some block on sending during airplane mode that needs to be removed.
We understand looking to use all your services. While on Wi-Fi, message plus should work to send text messages. This could be a block on the software of the device itself. Have you tried removing and installing the application? Have you tried restting your network settings? It may be best to contact Android or the device manufacturer to see if this is an issues with the software itself. It may be fixed in future updates.