The ad screen has some text, a [back] button on top, a [cancel] and [accept] button on the bottom center. I uninstalled all the recently installed apps. But still keep getting it.
I started getting it recently.
iPhone 6s, iOS 12
That sounds like what was called a Flash SMS, and is illegal in many locations. It is not an ad, but something else. I would try making sure you have cleared all History and Cookies.
You're welcome. Glad you got it straightened out.
Thanks @ChrisJ4203, ur a genius..
I referred the below link to stop flash sms, and solved my issue.
https://www.geekdashboard.com/stop-flash-messages-iphone-and-ipad/
I keep getting full screen ads even when screen is locked
