FaceTime mutes the other side when I speak?

Hello izabela3909,

Ensuring you're able to continue hearing the other individual on FaceTime calls is important. Since having this issue have you confirmed you're running the latest iOS? If not, update via the steps listed below.

1. "Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see two software update options available, choose the one that you want to install.
5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do."

Update your iPhone, iPad, or iPod touch

If you're running the latest iOS already, the next step would be to restart your iPhone. You can find those steps listed below.

1. "Press and hold either volume button and the side button until the power-off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo."

Restart your iPhone

Let us know how that goes!