You either have the stock(s) in a portfolio with email alerts turned on. Click on the portfolio and select the alerts icon to edit.

Or you are requesting alerts on the stock. Click on your username/logo in the top right and select e-mail alerts.  Turn off the tickers you do not want to receive alerts on.

Paid users have the same problem.

An inelegant workaround: from the SA home page scroll down to see "Articles you've Read". If there are new comments you can click through to the article from there.

Note you'll have to wade through all the articles you've read and not just the ones you are tracking.

Seems to be fixed now. Plus previously posted comments are correctly spaced.

I am seeing it too.

All line breaks are being removed