fonts.googleapis.com/css Not Found

I ran a link checker and it came up with

link has target url: "https://fonts.googleapis.com", link text: "[linked file]" and status: 404 not found
?
There are 33 occurrences of this link on other pages.

Besides the 404 Not Found problem, searching for and waiting for the fonts to download is slowing down the page load. Is there any way to speed it up?

I found where the call is coming from in the functions.php

		if ( $fonts ) {
			$fonts_url = add_query_arg( array(
				'family' => urlencode( implode( '|', $fonts ) ),
				'subset' => urlencode( $subsets ),
			), '//fonts.googleapis.com/css' );
		}
		return $fonts_url;
	}

I recently changed protocol for the website to https. Would it improve the search for fonts.googleapis.com if the https protocol was added to this in the function?
I searched for information in Google’s API documentation at https://developers.google.com/fonts/docs/getting_started and they use the https protocol in all their examples.

Or would it help to add a link to the Google fonts api to the header as they show in their example:

<link rel="stylesheet"
          href="https://fonts.googleapis.com/css?family=Tangerine">

substituting Montserrat for Tangerine?

The page I need help with: [log in to see the link]