"test" notification on my phone this morning?

On March 7th, some Android users reported receiving a "test" message from T-Mobile Diagnostics. This message was delivered by accident and will not affect the device. We apologize for any inconvenience and, if you haven't already, feel free to dismiss the message.

I had a test also on cell phone. When I clicked on it it wouldn't open. Also had a black dot symbol (looked like a camera icon) on top. Hmmm. What IS the Test TMobile? 

Same. Appeared at 11:22 AM EST. Then another tmobile notification popped up with content hidden. I'm not using my password to access that. 😒 

Had the same thing, 2 of them back to back. I dont recall the time. It looked like it came through the T-Mobile app judging by the logo. Clicking on it just cleared the notification and did not open anything. I then received a spam text saying there was a "69 minute Ts-Mobile service interruption" and to collect a free gift on them with a link that was clearly not a t mobile web address. One thing i do know for sure is dont expect T-Mobile to tell you anything regarding if it was legitimate or not.