What does the small red dot by the cellular bars on the upper right mean when you’re on a call? Also, the screen turns to the dark mode when the red dot is on. The call was not started in dark mode. Does this mean the call is being recorded or being spied on by a 3rd party? How can you turn it off while you are talking?
[Re-Titled by Moderator]
iPhone 13, iOS 17
Hello~ No. When you make a call the microphone is being used. See below…
Status icons and symbols on your iPhone - Apple Support*
*If you see orange or green indicators in the status bar
With iOS 14 and later, you might see an orange or green indicator in the status bar on your iPhone. These indicators appear when the microphone and/or camera are being used by an app.
An orange indicator 
means the microphone is being used by an app on your iPhone.
A green indicator 
means either the camera or the camera and the microphone are being used by an app on your iPhone.
To explain why the screen goes black click on and review *ProustGiulio’s* post as they explain far better than I could…
iphone X screen goes black during call - Apple Community
~Katana-San~
You asked what the red dot means "when you're on a call?" It simply means you are using the microphone, which is required for someone to be able to hear you when you're on a call. It is not in any way indicative of needing more security or of you being hacked. ANYTIME you are on a phone call, the red dot will appear.
Unless you have handed your phone over to someone, the chances you've ever been hacked are virtually impossible.
Thank you so much for that information. My phone has been "hacked" before, and I believe someone goes into "dark, private mode" to record my conversations. I did not turn on the recorder or mic., so someone may be doing it remotely. I need to get more security. Thank you for your info.
Hello~ I think your iPhone is working as designed and not hacked at all. I can understand your unease but I don’t think you have a reason to be worried here. Take care.
~Katana-San~
Thank you, but it doesn’t appear while I’m on a call. It appears any time. It never appeared while on a call.
Red dot and screen goes to privacy dark mode on some iPhone 13 phone calls
