I think this is something to do with the markup. I built this simple / minimal example:
<html>
<head></head>
<body><a href="https://twitter.com/share?url=https://us-gov.blogspot.com/2017/03/former-trump-advisers-offering-tweet_14.html&text=Former%20Trump%20Advisers%20Offering%20%27Tweet%20Risk%27%20Protection%20|%20Morning%20Joe%20|%20MSNBC" class="data-share-button">wibble</a><script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script></body>
</html>
That seems to work fine, so I don’t think this is to do with the pipe | character - not sure what is missing from your page.