I have a Samsung Note 9, recently updated to Android Pie. I disabled the SMS permission in the phone app, but it is still sending texts to 7723 all the time. I’m on the basic plan and pretty much all my texts for the month are used up. Any help would be greatly appreciated.
Check all apps for anything SMS and then disable SMS in each one by one until you find the one at fault. Maybe try a different dialer. Maybe a different texting app.
It might also be that the read confirmations and such are using one.
Also be aware that writing long missives count as multiple texts.
I just joined PM and my phone initially sends several texts to 7723 after activing and transferring my old phone number. I then setup voicemail, disabled the SMS permission for the phone app and restarted my phone. The texts stopped, so probably one of those things helped. Even after I reenabled SMS in the phone app, the 7723 texts are gone. I'm using the Essential phone on Android Pie.
Looks like the 7723 texts have returned, so it's back to disabling SMS permission in the phone app.
Regarding Oneplus users, I managed to find out how this bug happens and submitted to Oneplus in late February. They have fixed it in the latest update for OxygenOS 9.0.5. (I am using Oneplus 5T.) Tested working.
Please refer to the changelog 'Phone - Improved stability for the Phone app'.