You'll notice in Grow Social version 1.19.2 there is a notice letting you know of changes coming to share counts for Twitter in version 1.20.0.
What does this mean?
This simply means that share counts for Twitter will no longer be supported in the free version of Grow Social. If you'd like to retain Twitter share counts, you can upgrade to the paid version, Grow Social Pro! Just head over to the Mediavine Marketplace to upgrade.
As of right now, share counts for Facebook and Pinterest will continue to be supported. You can read more about how share counts work here!