Hi yusuffromilford,
Thanks for posting. We understand you're seeing an alert about microphone use when you open Control Center on your iPhone. We'll be happy to look into this with you!
Generally speaking, it's normal to see an alert like that when an app has recently used the microphone, but you should be seeing the name of the app as well. To clarify a few points, when you say you reset the phone, what process did you use? Are you referring to restarting the iPhone, or restoring it? If you restored it, did you restore a backup after, or did you set the iPhone up as new?
You mentioned this happens intermittently. How often does it happen? Does it happen after you've used a specific app or function on your device?
Also, when you say you're using the latest iOS, is that iOS 14.4.2? You can check under Settings > General > About.
Let us know! Cheers.