The app connects to the wrong device (like an Apple TV)
Open the device picker and select your iPhone directly. When the phone is plugged in over USB, the cable connection takes priority. Make sure the cable supports data, not just charging.
My iPhone doesn't appear over USB
Unlock the iPhone and tap "Trust This Computer" if prompted. Try a different cable or port because many third-party cables are charge-only.
My iPhone doesn't appear in AirPlay
Start the AirPlay receiver in the Mac app, then open Screen Mirroring on the iPhone. Both devices must be on the same network; guest networks, VPNs and network isolation can block discovery.
Mirroring feels laggy
USB gives the most stable, lowest-latency session and supports control. For AirPlay mirroring, distance from the router and congested networks are the usual causes.