Front-end Registration Not Saving User Meta

I have custom front-end registration on my site, and UMM automatically adds the additional field I need to the form, but it does not save it upon registration; it’s empty. It works fine when users register through /wp-login.php?action=register.

Here’s my registration form code:

<div class="register-container">
	<h2>Register</h2>
	<form action="<?php echo site_url('wp-login.php?action=register', 'login_post'); ?>" method="post">
		<p>
			<label for="user_login">Username</label>
			<input type="text" name="user_login" value="" id="user_login" class="input" />
		</p>
		<p>
			<label for="user_email">Email</label>
			<input type="text" name="user_email" value="" id="user_email" class="input"  />
		</p>
		<?php do_action('register_form'); ?>
		<input type="submit" value="Register" id="register" />
		<hr />
		<p class="statement">A password will be emailed to you.</p>
	</form>
</div>

Any help would be appreciated.

https://wordpress.org/plugins/user-meta-manager/