Problems with HTML

Since the latest updates (2.3.3) and WP 4.2.2, there are problems with the layout of the events. After adding or editing an event, the heading doesn’t appear like the way before. The heading appears as plain text – no color or anything. If I add html-code to change it, it doesn’t work. The html-tag is in the heading then in plain text, too.
In the editor window, in the ‘text’-sight, you can find html-tags as well, which haven’t been there before.
e.g.

Main sections:

• Science state of the art, progress from science into economical applications.
• Production technologies.

Thanks for your help!

https://wordpress.org/plugins/wp-events/