JSON_EXTRACT fails to handle specific escaped unicode sequence. Here is a example:

SET @str = "{\"\\u00e4\\u00f6\":\"yes\"}";

SET @path = "$.\"\\u00e4\\u00f6\"";

select @str, @path, JSON_EXTRACT(@str, @path);

Here JSON extract returns null. I've testet the same code on mysql and it works fine. The next example, containing only the first unicode character runs fine on mariadb and mysql.

SET @str = "{\"\\u00e4\":\"yes\"}";

SET @path = "$.\"\\u00e4\"";

select @str, @path, JSON_EXTRACT(@str, @path);