German and Czech mixed together

I have a form in several languages with English being the default langauge. I finished the German version,checked it was correct and started working on the Czech version. I noticed that when I start editing an item not yet translated into Czech, it has the German translation prefilled which is something it did not use to happen. It used to have English prefilled. I worry that this is causing the problem described below.

Now that I competed half of the Czech version, I can see that the German and Czech translations are randomly mixed toghether. The Czech version is OK, just the GErman one has some of the german translations overwritten with Czech.

What can I do to avoid this problem in future? This is not the first time that some translations disappeared with this form.

I checked this, the Czech on German Translation is actually like that in the settings so I don't think they are mixed up. I am doing a test now. I'll let you know later. 

The translation is working correctly, as far as I could see it. Here's a quick test using the same terms from your form:

https://form.jotform.com/70254362915960

The translations are mixed up in your translation settings upon checking. I would suggest going through each language and fix it there.