This issue is valid for all our (and not just our) plugins: WatuPRO, Arigato PRO, Namaste! LMS, Hostel PRO. The Jetpack contact form is causing all rich text editors used from plugins to freeze.
The bug is discussed in this thread and as you can see it affects users of many other plugins too.
To solve it use the plugin suggested in the thread.
We have been overloaded with emails due to this so support can be slower than normally.