(Occurs in TYPO3 8.7.17 and TYPO3 8.7.19 both PHP 7.0.32, I expect the bug to also occur in 9.5 LTS but have not yet tested that.)

Symptom¶

If you want to translate two content elements from one language to another and both are shown in the translation manager but not only one gets really translated.

How to recreate the bug¶

First create a test-element and translate it to any language you want.
Then change the language of the the translated element to the default language, which should in my opinion not work. But thats only my opinion.
Next press the translate button again. You will see both elements in the wizard but only the original element would be translated.

So whats now the bug.¶

In my perspective we are encountering two bugs here. First that the language of a translated content element can be changed, second that both (the original and translated) elements are shown in the wizard but only one gets really translated.

I have made a video as an step to step manual which you can find in the file section below.