I managed to fix this concerning issue on my device, so I hope this article helps others in a similar situation. This only really impacts you if you are on the $10 plan which has a limit of 50 outgoing Text Messages per month...
Quick Background and Problem Description
On the same day I activated my new phone I noticed on my Account Overview there were 21/50 text messages reportedly sent. This was very concerning as I didn't send any text messages explicitly and my limit was depleting fast!
After investigating my Usage History on the self serve website, I discovered multiple text messages reported as sent to a Destination # of "7723" and a Usage Type of "Minutes" as shown directly below:
I searched in the PublicMobile Community and discovered that on some devices, the "Phone" app on your device will automatically ping a text message to 7723 upon a device restart. And as my device was brand new, it was indeed restarting often while I was applying all the firmware upgrades, so this made perfect sense...
In order to prevent this from happening again and continually depleting my limited text messages, you need to disable the SMS feature from the specific Phone app on your device as shown below (for an Android device):
Now, when I restart my device, it no longer automatically sends text messages to 7723!
If you find this is happening to you, I would also recommend messaging the kind folks at the Moderator_Team via this link to investigate your account and to provide some additional insight into your issue. They were nice enough to reset my text usage count on my account so my limit was unaffected by this issue. Great customer service!!
It helps to provide a detailed description of your problem and what your resolution goals are so they can best assist. If you are having troubles contacting the Moderator_Team, refer to the following knowledge base link.
@John5859 Any Visual Voice mail option anywhere? maybe under Phone Settings, maybe under Message settings
apparently 7723 is the phone trying to confirm with the server if Visual VM is available. If it is, then it won't send again. Since PM does not have it, the device not smart enough to stop it, it will just send again every reboot
I previously noted that the texts came in groups of five or so, each a minute or two apart then they would stop for a while - probably until I used the phone again. The last message today was at 1:44 and it would have been the start of a group. I changed the setting around 1:45 and did a factory reset. I am happy to report that the texts seem to have immediately stopped. Nothing for the last hour and a half.
If that changes I will report back, but this really seems to have solved it!