Catalog Product – EDIT & SAVE – Multiple Store – only default CONTENT

We had to upgrade to Magento 2.2.9 recently.
It is a multi-language store, with DE and EN content. (store-view)

Product descriptions in

CATALOG-PRODUCTS-CONTENT

are DE in DE-store and EN in EN-Store.

We use default value for EN, then switch the STORE-VIEW on the top to DE, disable the default button for CONTENT in DE store and enter the DE description in the content.

All worked fine so far in previous Magento versions.

But for 2.2.9 when disabling the DEFAULT Button for CONTENT, the text box still stays gray.
We can enter text in gray and save. But when refreshed, the DE text is gone and the button is back to DEFAULT.

The DESCRIPTION text box should switch to black when default check-box is disabled, right? But it stays gray.

What’s wrong?

We checked older products where CONTENT field in DE store is populated and default button is disabled. Content text field is black there, but when enabling default button, the text field stays black. It should be grayed-out, right?

Thanks for any help.