Problems with line break after recent wordpress update

Hi!

Since the latest wordpress update that happened in the last few days, the line breaks on my blog (hosted on wordpress.com – which is why I didn’t choose a version when posting this) have gone all weird on me. I use the regular, unmodified twenty fourteen theme.

This is how it looks now: image link

I use the old editor on html mode and to get a simple space between paragraphs, I’ve had to use two <br> tags. I suspect some change in the latest update has changed how wordpress treats those tags?

So now all my posts (100+) looks awful. Was this change intentional? If so, am I really supposed to go through hundreds of posts and manually change every line break?

I’d appreciate some help, thanks.