Why keyboard disappears after entering one value (React Native Expo)? - react-native

Question

I'm making a login form in React Native. I can login and register already but when I try to enter values in the TextInput fields in my register form, the keyboard disappears after I enter one value, so I have to re-click every time on the input field to re-open the keyboard. This does not happen on Android, just with iPhone.
The weird thing is that this behavior does not happen on the login screen even though it is built exactly the same. Does anyone have any idea why this is happening?
Register.js
return (
<View>
<TextInput
style={styles.input}
value={username}
onChangeText={(text) => setUsername(text)}
placeholder="username"
returnKeyType="next"
/>
<TextInput
style={styles.input}
value={fullname}
onChangeText={(text) => setFullname(text)}
placeholder="full name"
/>
<TextInput
style={styles.input}
value={password}
onChangeText={(text) => setPassword(text)}
placeholder="password"
/>
<PasswordStrengthMeterBar password={password} />
<Button title="Register" onPress={handleSubmit} />
</View>
);
Login.js
return (
<View style={styles.container}>
{this.state.showComponent ? (
<View>
<Text>
<Register setShowComponent={this.setShowComponent} />
</Text>
<Pressable onPress={this.handlePress}>
<Text>Login</Text>
</Pressable>
</View>
) : (
<View>
<TextInput
style={styles.input}
value={this.state.users_username}
onChangeText={this.handleusers_usernameChange}
placeholder="username"
/>
<TextInput
style={styles.input}
value={this.state.users_password}
onChangeText={this.handleusers_passwordChange}
placeholder="password"
secureTextEntry
/>
<Button title="Login" onPress={this.handleLoginPress} />
<Pressable onPress={this.handlePress}>
<Text>Register</Text>
</Pressable>
<Text>{this.state.response}</Text>
</View>
)}
</View>
);
I already updated my phone, but that has not solved anything.