By default JetPack adds a nofollow attribute to all links in the related posts section. You can use this PHP code snippet to remove/disable this nofollow attribute.
JetPack
Remove Fading Of Images In JetPack Related Posts
The developers of the JetPack WordPress plugin decided to put a layer above the featured image thumbnails of “related posts”. This gives the images a faded look which you may not like. The CSS snippet shared here will help you disable this feature.
Six Reasons Your WordPress Site Needs Jetpack
Automattic’s Jetpack plugin has been around for a long time and grows with every new version. But why would anyone install such a massive plugin when there are smaller alternatives? This article looks at six reasons why Jetpack is still the go-to choice for the majority of WordPress-based sites.