Hi,
thanks for your question, and sorry for the trouble.
The cause for this is most likely some interference by another plugin or your them. By default, the word “H?chstgeschwindigkeit” would internally be saved as “H\u00f6chstgeschwindigkeit” (note the extra \
). There, the \u00f6
is the Unicode representation of the letter ?
.
Unfortunately, some plugins and themes wrongly use a PHP function like stripslashes()
on the content of a post or page in WordPress, and by that remove the necessary \
character. After that, the conversion back from the Unicode representation to the actual character fails.
So, you will have to find the plugin that causes this on your site.
Can you therefore please try saving a table with such “?” again, after temporarily deactivating all other plugins and after switching to a WordPress default theme like Twenty Sixteen?
Regards,
Tobias