Many factors could contribute to this:
1. Did the content change?
2. The on page optimization ( meta data etc,) change?
3. Were these previously orphaned?
4. Did these internal links add schematic and logical value to the theme of the website?
Did you use fetch as Google once these links were updated and /or were canonical URL's changed by this structure? More than likely this is just a boost because Google followed the new links, yet found the same page. The 'new' information needs to be reevaluated and ranked by Google. I'd give it 7-9 days and if no further movement, look to significantly improve the schematic structure of the website. Next, update the sitemap and resubmit the canonicalized URL's to Google through Google Search Console.