Option page not updating multiple records in settings api - wordpress

Question

Hi i am new to wordpress plugin development. i have issues with settings api. please help if you can.
Below is my problem.
The problem i am facing is the last record which is link it is updating in database but the title text is not updating in database.
So please help me find solution. Thank you.
function load_plugin() {
add_settings_section('plugin_main', '<h1>Ticker Settings</h1>', 'plugin_section_text', 'plugin');
add_settings_field('plugin_text_string', 'Title text', 'plugin_setting_string', 'plugin', 'plugin_main');
add_settings_field('post_title_link', 'Link', 'plugin_link_setting', 'plugin', 'plugin_main');
register_setting('plugin_options', 'plugin_options');
register_setting('post_title_link', 'post_title_link');
}
function plugin_section_text() {
echo '<p>Change your post ticker title and give link to.</p>';
}
function plugin_setting_string() {
echo "<input id='plugin_text_string' name='plugin_options' size='40'
type='text' value='" . get_option('plugin_options') . "' />";
}
function plugin_link_setting() {
echo "<input id='post_title_link' name='post_title_link' size='40'
type='text' value='" . get_option('post_title_link') . "' />";
}
add_action('admin_init', 'load_plugin');
function post_ticker_setting() {
?>
<div class="wrap">
<form action="options.php" method="post">
<?php
settings_fields('plugin_options');
settings_fields('post_title_link');
do_settings_sections('plugin');
?>
<input name="Submit" type="submit" value="<?php esc_attr_e('Save Changes'); ?>" />
</form>
</div>
<?php
}

Answer 1

You have to register all settings with register_setting (https://codex.wordpress.org/Function_Reference/add_settings_field). The register_setting lines you show don't correspond to your fields.
Also sections should be declared after the fields are registered (https://codex.wordpress.org/Function_Reference/register_setting)
In your code, the following lines
<?php
settings_fields('plugin_options');
settings_fields('post_title_link');
do_settings_sections('plugin');
?>
don't correspond to the declarations above:
add_settings_section('plugin_main', ...
add_settings_field('plugin_text_string', ...
add_settings_field('post_title_link', ...
Only the 'post_title_link' has the same name. Which is probably why it is the only one updating.